Problem: Some piece (or pieces) of rogue software have cluttered up your Open With contextual menu, which you can see by right-clicking or control-clicking any document in the Finder. This problem seems to be most prevalent with virtual machines that allow you to open documents with Windows applications, but tend not to clean up after themselves. After having both Parallels and VMWare installed on my MacBook Pro, my Open With menu was a mess.

Solution: Lucky for me, I noticed David Chartier's question about this on Twitter around the same time as I was wondering what to do about it. Some friendly person pointed him to a posting on Apple's discussion forum (also noted on Mac OS X Hints here and here), noting that running a specific command in a terminal window will rebuild your launch services, which repopulates the Open With menu with a current list of applications, without duplicates. It worked perfectly for me, but beware, on my system it took about 10 minutes to complete, and I suspect it could take more on a sufficiently gummed-up system.

Here's the Leopard version of the command (the path to the tool is different in Tiger, see here). I broke it into three lines for readability, but the \ at the end of the line is bash-speak for "keep on going with the same command" -- you can copy and paste it directly and it should work, or if you type it on one line without the backslashes, it will also work fine.

/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/\
 LaunchServices.framework/Versions/A/Support/lsregister -kill\
 -r -domain local -domain system -domain user 

If, preferring to avoid the Terminal, you want a handy GUI app to rebuild the Launch Services database with a couple of clicks, check out Titanium's OnyX or Maintenance utilities, both free of charge.

The blog Tap Tap Tap has posted a wonderful list to 10 iPhone tips and tricks you should know, including taking a screenshot (here's our how-to on that trick), enabling caps lock and customizing the home button's function. Definitely check it out.

While we're on the topic, here are a few of our own favorites

• The homescreen shortcut in firmware 2.2. With a click of the home button, you can jump to your first home screen.
• How to enable passcode protection. It's bad enough that you left your iPhone at the post office. At least the shmoe who finds it won't be able to call China.
• Pause an application download. Because sometimes you just don't have a free 90 seconds.
• Go Geocaching with an iPhone 3G. Who needs an additional GPS device?

Is your favorite trick not on either list? Let us know!

It's no surprise to most Mac users that you can use arrow keys to navigate through Finder windows. Arrow-key presses work in all three window styles: icon view, list view and column view. What many new Mac users don't realize though is that there are Command versions of these arrow keys.

When viewing folders using icon view or list view, both Command-Up-arrow and Command-Down-arrow play a special role. Command-Up-arrow moves you up to the parent folder of the currently-displayed folder. So if you are in, say, /Users/ericasadun/Pictures/Family, Command-Up-arrow would take you to /Users/ericasadun/Pictures. Press Command-Up-arrow again and you move to /Users/ericasadun. You can check your current folder by command-clicking the icon at the top of the folder window.

Command-Down-arrow only works when the selected item is a folder, and, like Command-Up-arrow, only in icon and list views. Pressing Command-Down-arrow opens and selects the current folder. So it essentially does the opposite of Command-Up-arrow. It moves you further down in the folder hierarchy as opposed to Command-Up-arrow which moves you up the folder tree.

These are useful shortcuts to have at hand when you prefer to use the keyboard to navigate through your files rather than the mouse.

Yesterday, I figured out how to record audio on the iPhone. Today, by popular request, I'll go through the how-to part. And, for those of you paying close attention, I've updated the application with lots of nice new features. For those of you playing along at home, here are the basics you'll need to know to get started with audio recording.

Tyler over at iPhoneology went diving into the iPhone's firmware, and found a preference file called "DefaultApplicationState.plist," apparently a list of widgets placed by Apple inside the iPhone.

Except that there's a few that we can't actually use yet...

com.apple.unitconverter
com.apple.widget.phonebook
com.apple.widget.translation
com.apple.widget.worldclock
com.apple.mobile.radio

That mobile.radio one looks especially enticing-- while built-in FM radio would be nice, it's more likely that Apple is expecting the iPhone to support streaming radio, just like that already found in iTunes.

Of course, this is all just speculation-- just because Apple laid out plans in the software for features like these doesn't mean that they're actually coming. And as a few folks have noted, they could just be holdovers from Apple's translation of OS X to the iPhone firmware. But because we know that more widgets and features are planned for the iPhone, these could be the groundwork of things we'll see implemented later.

Thanks, Reggie!

Welcome back to Mac 101, the TUAW classroom full of Mac tips for beginners (and veterans who might have forgotten them). Commenter Kris noted on a previous Mac 101 post that we hadn't mentioned the obvious: Apple has a collection of basic Mac tips, also called Mac 101. In our defense, we did blog about Apple's version almost two years ago.

Apple's Mac 101 tips are organized by topic, walking a novice user through initial setup and various Mac OS X features, as though you were paging through the manual; you can see a complete list here. An accompanying collection, Switch 101, covers hints specifically for switchers from Windows. The level of instruction in the Mac 101 hints? Well... here's the intro to the Ports and Connectors article:

On the sides of your Mac are a few small, geometric-shaped holes on your computer that may differ from one another. These are your computer's ports, which are used to connect other devices (aka peripherals) to your Mac. You've probably heard the words "FireWire" and "USB" tossed around at work or your local computer or electronics superstore, but what exactly do these terms mean? This lesson will tell you.

Ah yes, the geometric-shaped holes, I've been wondering about those! Elsewhere on apple.com, you'll find the Pro Tips section, mostly culled from Scott Kelby's well-regarded Mac OS X Tiger Killer Tips book. We'll pick some winners from this list for a future Mac 101 post.

One of my recent posts showed you how to rotate videos shot in portrait orientation. While this technique restores your video to its proper orientation, the results are not particularly usable in your favorite video editing programs like iMovie because of their unusual aspect ratio. The following gallery demonstrates how to matte your video onto a plain background using QuickTime Pro to restore a proper 4:3 (or 16:9) ratio.

Mac Hints & Tips is a killer site that catalogs (of all things) over 6,000 hints, tips, workarounds and other handy pieces of Mac OS X trickery. Compiled from Mac user groups, Apple websites and various other published and unpublished sources around the globe, this highly bookmarkable (and subscribeable) resource is run by one mere mortal by the name of Paul Taylor, who is seeking donations and subscriptions to keep the site and monthly PDF truckin'. Paul currently allows users to sign up for a yearly membership to gain access to the entire database of tips, searchable by keyword or application name, and he also accepts good ol' fashioned donations (though we've all seen how well those go), but he's trying to get the word out to see if the community can toss a few more dollars into the bucket o' hosting bills. To see whether Mac Hints & Tips could be worth your time and a donation or a membership, Paul keeps archives of the past three months available on the main page (in both HTML and PDF), in addition to the current issue.

Check out Mac Hints & Tips, as I know I've found it to be an invaluable resource over the year or so I've been a reader, and it would be great to see such a killer resource get credit where it is most certainly due.

The Omni Group has hinted at new products and teased us with a handy tool and toy. While 3rd party solutions have existed to turn their OmniOutliner Pro into a mean, lean Getting Things Done machine, the Omni Group has finally spilled the quintessential bean in a recent blog post and confirmed that a true-blue GTD app is in the works, and its name is OmniFocus.

However, I say the Omni gang spilled one bean - and one bean only - because they have twisted the cruel rumor knife ever so slightly by withholding any other details. No features, no clues, no ETA or price range. Not even a blurry icon. Cursed Omni Group! For now, it seems, you have forced us to suffer in your dungeon of anticipation! Our only salvation is your humbling generosity - some day - offering the warm sunlight of more details. Oh despair - thy name is OmniFocus!

The 'don't-buy-a-Mac-without-it' macosxhints.com has debuted a hint rating system, allowing both logged in and anonymous users to place a 1-5 star rating on each hint.

As you might expect, their stats page now includes a 'Top 20 Rated Hints' section at the bottom. This should allow you to spend even more time you never intended to, learning even cooler ways to use your Mac.

The invaluable macosxhints has received a redesign and feature boost. The site's theme has received a stylistic bump, and legibility has improved site-wide. New functionality and features include more topic categories and a better search (while Rob won't use the term 'better', I will). Registered and logged in users will likely welcome simplified account management tools and more control over what information you include and display for others.

Head over and take a look at macosxhints' new look and add your $0.02 to their announcement post.

The Omni Group has begun hinting at a new product on their blog by offering clues on their blog as to what it is not. In posts like A trickling of inklings, they have let us know things like the product's sub-$20 price, that it is not a replacement for Mail and that it has nothing to do with the iPod. They also have plainly stated that they have other new products and updates for existing products planned for 2006. This should be good news for those of you who (like me) are fans of their excellent offerings like OmniGiraffe OmniGraffle and OmniOutliner. Here's hoping they don't keep us in suspense for too long.