We're getting tips from multiple sources that Apple has invited a group of iPhone developers to test drive AOL's updated Instant Messenger app for the iPhone -- complete with push notification -- in an effort to see how Apple's servers will handle the traffic. The invitation included the following:

"As a developer actively working with iPhone OS, we would like your help in a private test of the Apple Push Notification service. For this test, we have selected AOL's AIM Developer Preview for iPhone OS 3.0 to create a high-volume test environment for our servers."

Digg's Kevin Rose, perennial purveyor of information that just "fell off the back of the truck" shared a link early this morning to Google's new, supercharged, Webkit-based browser -- for Mac.

The new browser, Chrome, is clearly marked as a developer preview, and not meant for general browsing. In fact, as a good Mac citizen, it will refuse to set itself as your default browser.

It scores a 100 on the Acid3 test straight out of the box, but doesn't pass: it fails something called the linktest, which involves interacting A tags and IFRAMEs. A little research suggests that it could be a bug with Webkit. If that's true, then it's a bug that Safari 4 beta has fixed.

Chrome appears to have Flash (and other plugin) support disabled as well. JavaScript support, however, is fully functional. While Chrome performed much better than Firefox on this cursory test, it still didn't beat Safari 4 by a long shot. While only a beta, its performance is respectable and sure to improve.

Again, Google Chrome isn't for everyone, but if you're a web developer who needs to keep up with the bleeding edge of browser development, then this preview should be stable and reliable enough for you to test what you need to.

Read through for the full JavaScript test details.

Thanks to everyone who sent this in!

While still in beta, Evom (from The Little App Factory, makers of iPodRip) looks ready to pick up where iSquint left off. It easily and quickly converts videos to formats compatible with iTunes, YouTube, your iPod, and Apple TV.

It couldn't be a simpler drag-and-drop operation: drop the video on the Evom window, and select a destination. After that, Evom does the heavy lifting and (optionally) adds the finished video to iTunes. The output quality is good -- it uses the same technical foundation as ffmpegX. You get the same high quality without all the fiddly controls of ffmpegX.

Evom also includes a bookmarklet that lets you save off YouTube videos to your computer with a single click. The quality of the output there mostly depends on how good the source video is, but it couldn't be easier.

iSquint, my favorite "as if by magic" video conversion tool, was discontinued after Techspansion (also the makers of iSquint's bigger brother VisualHub) shut their doors last October. The VisualHub codebase is still being developed, however, in a new project called Video Monkey that Aron covered in March, which is also well worth a look.

Evom is in beta, but unlike iSquint, it appears like it may cost something when the final version is released. It also appears limited to converting 60 items until it's registered, and trying to register the app leads to a non-existent shopping cart area. Even so, the simple interface and easy installation will be worth a few bucks to me.

[Via Daring Fireball.]

If you're a developer running the iPhone 3.0 beta, you may have gotten a special note in your email today -- and judging by the number of you who let us know about the news, there's plenty of those emails going around. Apple is testing the long-awaited push notification feature of the 3.0 software (and the back-end servers that provide the updates) with a build of the Associated Press news update app. If you got an email with a promo code and you've been putting the app through its paces, do let us know how it's going.

Push notification is all well and good, but what about true background processing for those critical applications that need always-on connectivity? More on the prospects for that capability in our next post, coming up shortly.

Thanks to everyone who sent this in.

[H/T to Engadget]

Version version, who's got the new version? iPhone OS 3.0 beta 5 is now downloadable, along with a new build of iTunes 8.2 -- log into developer.apple.com to pick up the latest build.

What's tweaked and changed? Well, editing the carrier file in iTunes to enable tethering is now apparently blocked, and MMS support on AT&T is also 'hidden' per the iPhone Blog. It's not 100% clear whether these feature drops are deliberate, as some reports say a clean install preserves the capabilities. Parental control features for apps now seem to be visible... and yes, the new beta has already been jailbroken.

Got more observations and tidbits? Let us know below.

Thanks to everyone who sent this in.

In the history of marketing battles, The Cola Wars have nothing on the Twitter App War that's currently raging online. Twitterrific, TweetDeck and others (popular with commenters: Pwitter and DestroyTwitter) are waging the ground battle, while Twitterrific (mobile), Tweetie and TwitterFon (to name a few) are fighting it out in the air.

Today we got our hands on a beta of Lounge, a new client for Mac OS X (and iPhone/iPod touch). It's definitely got a way to go (I saw more beach balls than Memorial Day at Hilton Head), but I see where they're going and I like it.

First off, there's support for multiple accounts, and switching between them is easy. A series of buttons appear horizontally in the left of the window, including "My 2 Cents" (which displays just your tweets), Favorites, Friends, Replies and my favorite, Vanity, which finds all occurrences of your Twitter handle.

Mouse over a user's tweet to see options to re-tweet, copy the URL, open in a browser and more. I really like the option to view user details, which lets you see just that user's tweets, his followers, those being followed and profile and URL.

It is kind of wide (wider than Twitterrific but not TweetDeck, of course) so those with small displays be warned. Also, some may be put off by the pastel-colored icons. Still, it shows promise. Check it out if you're up for it, and provide some feedback to make Lounge better.

Just as developers around the world are hearing about the new iPhone features, Apple has updated their Dev Center. With the new site, existing developers will get immediate access to the new iPhone 3.0 SDK. That is if you are able to login. Currently the Dev Center is experiencing extremely slow load times, and kicking some users off when they try to login.

It will be interesting to see if non-developers will register for the $99/year program, just to get access to the beta of iPhone 3.0. Be sure to take part in our poll below.

Since it's turned into Twitter Thursday around here... In a moment of sheer frustration with Twitterrific, I sent out a call on my Twitter feed for recommendations of a desktop Twitter client. Several folks replied with a nod to TweetDeck, an Adobe AIR-based client currently in development for OS X, Linux, and Windows.

TweetDeck is a pretty neat program. The selling point is the ability to split your main Twitter feed into subfeeds that you can then organize into different groups. You can have Twitter be as narrow as a single column while you scroll back and forth in it, or you can make it full-screen and have your monitor filled with nothing but tweeting goodness.

There's a lot of features as well. If you go over the 140-character limit, you can hit a "TweetShrink" button that will turn some of the words to LOL-speak in order to fit the limit. You can upload pictures -- clicking on the TwitPic button will upload the image file to TwitPic and give you the URL for your feed -- and you can shorten URLs via your choice of service by clicking the "Shorten" button.

Another very cool feature is the ability to translate your tweets into another language. The translation is pretty accurate -- even for more difficult languages such as the Japanese I tested with the application. The program itself is highly customizable, and you can tweak the colors and fonts to whatever you like. You can also set different update times for various feeds: for example, you can have your main friends update every minute, but your private messages every five minutes.

TweetDeck is extremely polished for a beta client and I've yet to get the error messages that plagued me with Twitterrific. If you're searching for a free desktop client for Twitter, it's hard to beat this one.

TweetDeck is in public beta and requires the Adobe AIR runtime, which is a Universal binary and needs OS X 10.4.11 or higher. AIR will be installed during the TweetDeck installation process if you do not already have it.

If you're in the market for a new email client to try, I mentioned Postbox a few weeks ago. Late yesterday, the Postbox team released beta 8, which features an improved conversation view, and new and improved support for QuickLook, Flickr, Hotmail, and Growl.

The beta also fixes many bugs found by users (including myself) and performance enhancements. Also, Postbox is heeding user suggestions to become more Mac-like, including keyboard shortcuts in menus, improved notification for unread messages in the dock, and the aforementioned QuickLook and Growl integration. Full release notes are available on the Postbox website.

Performance appears to be about the same -- which is to say pretty good -- and indexing on my 2006-vintage black MacBook still occasionally ramps the fans up to hurricane strength. I've been using Postbox as my primary email client for about three weeks, and its held up to my demanding workflow, but still has a ways to go before it becomes the killer email app.

Still, if you're a high-volume email consumer, Postbox is a solid option for you. Postbox is free (and will continue to be free, so far as we know), universal binary, and requires Mac OS X 10.4 or higher.

After waiting a day for the dust to settle -- and for developers to catch up -- since Apple's release of Safari 4 beta, it looks like there are relatively few show-stopping bugs to talk about. Just about every problem we've heard about at TUAW, and every issue I've had personally, has been an issue with a plugin. Fortunately, for those of us who really depend on hacks plugins for surfing productivity, most developers have been preparing for the release using nightly builds and have already come through with updates.

Yes, plugins break when software is updated, when the software is beta, and when -- due to the lack of a genuine plugin architecture -- plugins are, in fact, hacks. The developers of our third-party goodies have our backs, in most cases, and I expect the ripples on the water to die down completely over the next week.

In the area of search plugins, I switched from Inquisitor to Glims a while ago because of the extra features Glims offers. I haven't seen an update to Inquisitor yet, but Glims came out with build 13 this morning. Unfortunately, my search-as-I-type functionality still isn't working, but the plugin loads and the additional functionality is there. It's quite possibly a conflict with another plugin ... not that I'm running that many.

Why, you might wonder, would we want another media program -- isn't iTunes enough? But a new app called Doubletwist (by DVD Jon, creator of the old DeCSS DRM-stripping software) looks to answer that question by taking an iTunes-style interface, and expanding it to pretty much anything you'd want to do with media -- send it to your own phones and portable devices, upload it to sites like Facebook or YouTube, or even send it off to your friends, even those who don't have the app. We first heard about Doubletwist about a year ago, but there wasn't a Mac version to speak of (so who cares, right?).

But the Mac version is now out in public beta, and it's pretty impressive -- you can basically ignore file types, formats, or anything else that would keep you from sending a video, audio, or photo file from your computer out into the great blue yonder. There are a few other screencasts floating around as well, including this demo of the way the app works with pretty much any device you want, from iPod Blackberry to Android, the Sony PSP, and soon, the Nintendo DSi. [Note that the current build only supports the iPhone and iPod on the Windows side, but they say that Mac support for our favorite devices is forthcoming.]

It seems very enticing (though I'm doubtful that all of the video converting and sharing really goes as fast as it looks in the video). But if you want to find out for yourself, have at it -- DoubleTwist is currently a free beta download for Intel 10.5 and up users.

Thanks Sebastiaan!

Does anyone still actually use AIM to sign in to their AIM account? I've found the AIM Express client useful occasionally when I happen to be on a strange computer (though nowadays I mostly use the AIM iPhone client when I'm AWOL), but on the desktop it's been Adium for longer than I can remember.

Still, if you'd rather do the official way, AIM for Mac 1.1 is out now. There are a few bugfixes -- ICQ accounts had an issue signing in, apparently, and there were a few font and display issues fixed. And there aren't too many new features, though you can now leave notes in "Edit Buddy" fields and the Buddy List search got improved. Unfortunately, it looks like, according to the screenshot they posted, the Buddy List will also blur out all the names on your Buddy List, which seems really inconvenient.

The app itself is still in beta, though you can't really go wrong with instant messaging -- either your messages get through or they don't, right? You can download it now, or if you're already using the 1.0 client, you'll get notified automatically.

Disclaimer: TUAW is owned by Weblogs, Inc, a division of AOL. We were kidding about that blur thing, AOL -- we know it's just for the screenshot.

Postbox, the email client built for heavy email users, entered Public Beta on Sunday. Postbox is designed to allow you to search, organize, and manage your email more more efficiently.

Postbox includes a powerful search tool that lets you use Gmail-style search terms (like "from:Steve" or "before August 2008") to easily find messages. The Gmail-like features don't end there: Postbox automatically organizes threaded emails by subject. Messages can be tagged with one or more topics for easy recall later.

Perhaps Postbox's greatest feature is its ability to recognize what's in your email, and keep it front-and-center. For instance, if you're composing a new message, you can use the Compose sidebar to find attachments in other messages to drag into your new message. The inspector panel on the preview window highlights links, addresses and attachments in the message so you can get to them easily.

For me, I use my inbox like a to-do list. Thankfully, Postbox has a built-in Archive utility that lets you specify an archive folder for each account (which I already had set up). Once you're done with a message, clicking Archive or pressing A moves that message (or many messages) right into your archive.

Add to this to-dos, integrated search, social network integration, message annotation, tabbed browsing, and a high-security Mozilla foundation, and you've got an amazing Swiss Army-knife tool for hard-core emailers.

Wherefore art thou, Push? Macworld has gone in search of the much-awaited iPhone feature that would let applications get their own notifications even while not necessarily active (so apps like Twitterific could have a little red number on them showing the number of unread tweets, and so on). But the Push system was "pulled" (still makes me laugh) from the 2.1 firmware during the beta phase, and as you probably know by now, it's still not on your iPhone.

Unfortunately, there's no official news on the subject (Apple hasn't canceled the service completely, as far as we know, but would they really tell anybody if they did), but Macworld has a few ideas: it could be that Apple has abandoned the system, thinking that it didn't really help as much as they thought it would, or Apple is still working on it, or Apple is working on something even better. Which one of those you decide is true probably depends on what you think about Apple in general, so we'll let you make your own guesses on that.

But we will say this: we're near the end of the known roadmap for the iPhone, and people are already talking about a new version of the hardware. If we don't see an update on Push in the next refresh, it's probably likely that the only thing the notification system will be pushing is daises.

TypeDNA is previewing its advanced font management software at Macworld booth 4037, and gave TUAW a sneak peek.

TypeDNA (also the name of the product) is cross-platform, standalone font management software that also includes some advanced features to help you select fonts based on similarity and type features. Along with standard activation and grouping features, TypeDNA includes Font Harmony and Similar Fonts tools to help you select aesthetically-compatible fonts for your projects.

TypeDNA will begin a public beta program soon, with an eye to releasing the software in March. If you want to sign up for TypeDNA's public beta, you can.