From Newsforge:

While virtually all computer graphics professionals use Adobe Photoshop to do their artistic work, Photoshop is a pricey and proprietary application. If you're looking to do graphics design on a budget, or perhaps want a software package that is less resource-intensive than Photoshop, check out open source alternatives -- the GIMP, SodiPodi, and Inkscape.

Read the full thing here

I've been doing a lot of work with SVG as of late, and tend to prefer Sodipodi (maybe it's Gimp-like interface appeals to me....)