Can I use the the Windows version of Photoshop on my new Mac? Would those install disks be compatible, or do I have to buy a whole new Mac version of the program?
#1
Only if you've installed Windows on that Macintosh.
If you want to run Photoshop under OS X, you will have to buy a new copy, or cross-grade to change the platform for your license.
#2
But you'll likely be better off installing Windows until CS3 comes out. CS2 runs under rosetta which may or may not work well for you.
Bob
#3