GimpShop - Free alternative to Photoshop

At http://www.plasticbugs.com you can download the GIMPshop, which is a modified version of the GIMP, the GNU Image Manipulation Program. The GIMPshop version is meant to be more familiar to Photoshop users and is available, free and with sources, for all major platforms: Windows, MacOSX, Linux and even Solaris.

If you don't have the budget for Photoshop or even the smaller, but very usable Photoshop Elements, you can try to see if this program fits your needs.