I'm a web designer who tries to use free software without exceptions.
On GNU/Linux Debian i'm just a beginner, but my vision is clear: professional graphic design without any proprietary elements.
Yes, GIMP, INKSCAPE and co. aren't as powerful and comfortable as Photoshop and Illustrator yet, but i think that will change. When to begin, if not now?
Copyleft and and the philosophy of Richard Stallman are very inspiring tho me:
"Value your freedom or you will lose it, teaches history.
'Don't bother us with politics', respond those who don't want to learn."
"If anything deserves a reward, it is social contribution. Creativity can be a social contribution, but only in so far as society is free to use the results."