Welcome back to Ask TUAW, our weekly troubleshooting Q&A column. This week we've got questions about Photoshop alternatives, Windows and Mac file sharing, graphics problems in Snow Leopard and quickly switching between applications, and more.

As always, your suggestions and questions are welcome. Questions for next week should be left in the comments. When asking a question please include which machine you're running and which version of Mac OS X (we'll assume you're running Snow Leopard on an Intel Mac if you don't specify). And now, on to the questions.

Matt asks:

I don't have the money for something like Adobe Photoshop. What's the best, cheaper alternative?

For my money, the best Photoshop alternative at the moment, and one I use every day, is Pixelmator. It has many of the same features as Photoshop like layers, masks, level and curve adjustments and a whole lot more. Plus, it's a relatively simple program to use and is written to take advantage of your Mac's GPU when doing image processing.

It also supports most image file formats including Photoshop PSD files and has many useful Automator actions built in. Actually, because Pixelmator is such a good app and takes care of most of my needs, it's pretty rare that I ever open Photoshop anymore. Sadly, Pixelmator is not free, but at US$59.00, it's a heck of a lot cheaper than Photoshop.

Some other alternatives include the open source GIMP and its more Photoshop-like cousin GIMPShop. You can also check out Acorn, or if you need very minimal tools like crop and resize, ImageWell. Of course, Apple's built-in Preview.app can handle many of these low-end tasks as well.

Apple yesterday announced a new addition to Mobile Me: The ability to share large files with others via iDisk. One of our readers had noticed an announcement about it way back on New Year's Day.

The service works much like YouSendIt, though rather than uploading a file, you point to an existing file on your iDisk. MobileMe then assigns a URL to that file, and offers to send an email to a recipient with the link. You can also assign an expiration date and password to the link.

MobileMe's sharing functionality is so far only available only through the iDisk web application, and not through the Finder. Tools like Dropbox and FileChute -- available on the desktop -- allow you to upload files and assign them a public link, but don't feature expiration dates or passwords (yet).

Apple offers a tutorial on how to use the new feature on its website.

Thanks to everyone who sent this in!

Update 2: Box.net will work with first generation iPod Touch units. The team is going to push an update very soon to make this visible on the app description page. You can download the program right now and it is fully compatible with all iPhone and iPod Touch units.

Update: Box.net is looking into why its new app is not working with first generation iPod Touch units and hopes to push out an update soon. We'll keep you posted!

I love Box.net -- the online file storage system that makes it easy to store and share files with other users quickly and easily. A couple of years ago, TUAW wrote up how to use Box.net as an iDisk (and this still works), but now the Box team has made it even easier to access your files while on the go, with the new Box.net iPhone app.

The app, which is compatible with the iPhone and the second generation iPod Touch (sorry 1st Gen touch users!), is simply awesome. Box.net already had an iPhone friendly mobile interface at i.box.net, but while you could access some files from that page, you couldn't play back media and document viewing was more limited. The new application means you can play back audio and video (assuming the file is compatible with the iPhone 2.1's firmware support for QuickTime), view PDF or Office files, view photos, and upload photos from your iPhone or iPod Touch directly to Box.net.

Even nicer, the Box.net app integrates directly with your address book, so you can share a folder or individual document with a contact, just by clicking the "Share" button and selecting the contact from the address book. The application also notifies you of any updates or changes made to your box, which is great for individuals who collaborate with other users using a Box.net account.

I have a free Box.net account (which limits me to 1 GB of storage space and puts a 25 MB cap on file sizes), but I was able to access all my files and documents with ease. On my iPod Touch, Box.net loaded PDF files faster than some other tools I have used for PDF viewing, though I did find that network activity did impact overall speed. When the bridged router I use with my non-802.11n devices was in heavy use, it could take quite some time to load a large PDF. When the G router was idle, load time was almost non-existent, even for 8 or 9 MB files.

I don't have an iPhone, so I cannot vouch for EDGE or 3G speeds -- but over WiFi, speed was solid.

The interface of this app, as you can see from the gallery, is just superb. It perfectly matches both the Box.net website and the iPhone user interface guidelines. Maneuvering through files was a cinch and I love the integration with the address book for sharing files or folders. Being able to upload photos directly to Box.net is also pretty great.

If there was anything that could be on my wishlist, it would be the ability to upload other types of tiles to Box.net as well. Of course, you can always e-mail uploads to Box.net, so this isn't an absolute necessity.

Box.net is free and available from the App Store now.

Dropbox, my favorite FTP-free file sharing and transfer system, is now in public beta -- anyone can sign up to use the service, and you don't need an invite code.

Spokesperson Drew Houston said in a blog post that they launched the public beta at the TechCrunch50 conference in San Francisco.

I wrote about Dropbox in May, and it's still a regular part of my file transfer strategy with my clients. It's easy and fast, which makes it perfect for clients who don't want to spend a lot of time sending me files (or downloading them, for that matter).

If you need more than the free 2GB of storage, 50GB will be available next week for $10 monthly (or $100 annually).

Thanks, Josh!

I don't know about y'all, but the beta service Dropbox has personally answered my prayers. It's an amazing piece of web software that integrates with the Finder, and allows you to seamlessly copy files up to the web for sharing -- and not use FTP.

Dropbox exists (through some kind of magic, I'm sure) in your home directory as a folder named "Dropbox." There, you can copy files to and from it just as you would any other kind of folder. File copying is pretty perky. A 1MB file took about 15 seconds over my broadband connection. As someone who still cringes at uploading files via the Finder (hi, early .Mac user here), this was a pleasant surprise.

One thing I wasn't expecting was that since the Dropbox folder appears to "live inside" your home directory, the default Finder behavior of moving files (and not copying them, as you might expect) applies. I was still of the FTP mindset that "I am copying files to the internet." So hold down that option key.

Beta accounts of Dropbox include 2GB of storage. (If you need more, SugarSync, OmniDrive, or JungleDisk might be options for you.) You can also add multiple computers to the same account, and have access to a common Dropbox among all of them.

My favorite feature, though, is being able to upload files to a "Public" folder, and have a URL automatically assigned to them. I have a Transmit bookmarklet that already does this (though, it uploads it to my own website), but I have to type out the URL manually. Dropbox's contextual-menu item saves me that trouble, and I can just paste the URL into my email.

Dropbox is still in public beta, so if you know a friend who got a beta signup code, then they got 10 invitations as well. So bring chocolates, flowers, cash, or whatever it takes to get an invitation. They will disappear quickly.

Papaya is a new utility for personal file sharing, and TUAW got a chance to put through its paces. We were pretty impressed with the ease of use it provides for getting your files across the office... or the globe.

Papaya provides a simple window and a multitude of methods for adding files to be shared. You can drag on to it, manually select files, snap a picture with your iSight or add the currently playing track from iTunes. You can even paste text snippets onto it for quick sharing of code or prose. It allows for the creation of folders – which it can automatically archive and compress at the time of download – and a web interface for navigating remote libraries.

Papaya sets itself up as a web server on port 6900 and takes very little network configuration (you will have to map that port to your machine if you're behind an Airport base station or other NAT router). When you add a file to Papaya, it automatically copies an address to the clipboard (an option in the preferences) which you can send directly to another user. While I wouldn't recommend broadcasting that address far and wide, it makes for a very convenient means of getting a larger file where it needs to go, without dealing with an interim server.

Papaya provides Quick Look previews, and the web interface is iTunes-like and easy to navigate. It can also resize images and define its own folder hierarchy without disturbing your original files. The files are served from where they exist on your drive, everything else is handled on-the-fly. It even provides access control on a per-file basis. Basically, it's file sharing at its most personal.

If you need to share files with friends, family or co-workers quickly and conveniently, give it a shot. The download is free, but a license will cost 20 Euros which, with the current state of the U.S. Dollar, is almost $32. While Papaya is extremely fluid and well though out, I do think that's a bit of a high price point for a file sharing utility, especially considering it's a convenience layer over the built-in functionality of your Mac. Fluid to use and pretty to look at, to be sure, but you'll have to make the decision as to whether the convenience is worth the price.

QuickShareIt, which we covered a while back, has received an upgrade to 2.0, adding many of the originally promised features as well as a host of new ones.

QuickShareIt is a Mac app that provides online storage and file sharing with both Mac and PC users. It's growing up amongst a host of similar products, but differentiates itself by offering some unique features centered around the teaming of its dock icon drop-box, "recent uploads" floating panel and web-based file access. For example, if you drag multiple images onto the dock icon, it will ask you if you want to create a gallery. When the upload finishes (with Growl notifications), it will give you a url that you can share and provide options for handling that gallery in the floating panel. It also accepts text clippings and creates a line-numbered, online document for quick sharing of code samples or text snippets. Previews for other filetypes are available.

Right now uploading to QuickShareIt is anonymous and public access. The developers are rolling out registration options in the near future, as well as paid options with extra features. If you want to try QuickShareIt out, just download the application and run it. There's no configuration or sign-up necessary (despite the option being present), just drag files or text clippings onto the dock icon and watch it go.

Do you remember when Napster was huge (about ten years ago), and digital file sharing was on everyone's minds? Metallica and The Red Hot Chili Peppers were sort of leading the anti-p2p charge. Several years later, when the iTunes Music Store demonstrated that the online distribution of music could be accomplished successfully, the Peppers refused to participate, stating that (among other things), they didn't like that customers were able to purchase individual tracks, as it interrupted the flow of the album, or some other artsy thing like that.

Anyway, this is why I was very surprised to find nine Peppers albums in the iTMS this morning [iTunes link], including some exclusive stuff and videos. I'm glad you guys have come around.