This weekend, my cousin told me that he needed to do some quick and dirty layers-oriented graphic design, something that even the newly beefed-up Paint for Windows 7 couldn’t take care of.  He resorted to installing an old version of Paint Shop Pro 7 to get the job done.  While this was certainly an easy way to accomplish what he needed to do without procuring a copy of the ever-popular Adobe Photoshop, it made me start to wonder what other Photoshop alternatives are out there free for download.

Paint.NET – Only for Windows PC’s, Paint.net was originally designed by several undergraduates as a replacement for Microsoft Paint.  It is still maintained today and is an extremely popular free, layers-based graphics application.
The GIMP (The GNU Image Manipulation Program) – Originally designed for Linux as a Photoshop replacement (before WINE was working as well as it is now), The GIMP has now migrated over to Windows as well and remains the open-source movement’s leading graphics program.
Pixia – I admit I haven’t played with Pixia myself, but have heard about it from several different sources.  According to its Wikipedia article, it was originally developed for the anime community.  From what I understand, it sounds more like Adobe Illustrator than Photoshop, but it might be worth checking out if you can find a download in English (perhaps on C|Net?)
Inkscape – Designed as open source software similar to Adobe Illustrator, Inkscape is available for Mac OS X, Linux, and Windows.  Again, I haven’t tried this software myself but I’ve heard really good things.

Photoshop Express – Even Adobe realizes that Photoshop is an expensive piece of software that not everyone can afford.  For those quick photo retouches such as red eye reduction, cropping, rotation, or even some light balancing, check out Adobe-sanctioned, web-based Photoshop Express.
Aviary – Finally, saving the best for last,  Aviary is the all-in-one Adobe suite that runs lightning fast on a spectacularly designed web platform.  While it doesn’t currently have any options for editing video, it has just about every type of photo manipulation capability you can imagine.  It also has a nice audio editing utility that allows you to modify any imported audio files you may have.  This application is perfect for anyone who doesn’t have the time or resources to install Photoshop.