I agree Max it out. The less you have to access your scratch disk
in Photoshop the faster it will be. I run 1.5Gb of RAM on my Mac.
The Mac will only allow you to apply a max of 999mb to any one
program, I don't know if it's the same with a PC. However the
additional RAM gives you headroom to run additional software at the
same time which is a beautiful thing.
Bob
There is no such thing as "too much" of RAM for Photoshop. If you
are serious about image processing, 1- 2 GB of RAM is just fine,
more is even better. There is no upper limit to the amount of
memory allowed used for any program on the PC as far as I know, but
you do have RAM ceilings depending on the operating system
(commonly 4 GB on current Windows flavours, probably to be
increased when 64-bit CPUs become standard).
My next Photoshop-dedicated C should have 4 GB of RAM - at least.