I'm a long time Photoshop user. I started in high school in journalism class and I've been through several versions up to CS2 today. I love Photoshop to death. However, I run Linux now, and dual booting would suck. Qemu doesn't cut it eaither and I don't think Wine handles CS2 very well at all.
There is a program called GIMP, GNU Image Manipulation Program, for Linux that is equivalent and I've tried many times to come to grips with it's different interface. I used to despise GIMP, well, I still despise GIMP, but at least now I can work in it.
Here is my first piece of decent work to come out of gimp. A nice, shiny, flare-y, striped glass web 2.0 bar. It was a good learning experience and I thought I'd share it's beauty.