http://www.gimp.org/

 

GIMP is the poor man's photoshop. Has many of the same features, but it's free, open source software. The only thing it lacks is the plethera of brushes available to photoshop users, but if you do a web search, you can find a lot of them that were converted to work in GIMP.

 

EDIT: cross posted!

If I had a nickle for ever time a woman told me to get lost, I could buy Manhattan.