I own both a PC and a Mac
PC - WinXP and Mac - Jaguar OSX
and I am in the Graphics industry
I would just like to point out that the Mac is Significantly FASTER, and more STABLE with graphics applications (talking mainly about Adobe, Quark and Macromedia) than the PC. The OS is also more stable and capable on the Mac, enabling more apps to run simultaneously (whilst independantly), and smoothly than on the PC.
Whoever said that PCs are becoming more commonplace in the graphics environment is totally wrong... the only even graphics related place that I know of that has more than a couple of PCs running graphics software is Kinkos... and just go to any Kinkos and look at the amount of people that choose the PCs to use over the Mac.... not very many...
For comparison purposes both have around the same specs
P4 vs G4
2.4Ghz vs Twin 1Ghz
768 RAM 768 RAM
Nvidia GeForce 4 both
PCs are great tho... if you want to program, play a wide range of games or watch (but not edit) movies...