Greg: Thanks for the information. For now I'm looking at upgrading the processor and motherboard:
Processor:
Intel Core 2 Quad Q8300 Yorkfield 2.5GHz
Motherboard:
ASUS P5Q Pro Turbo
I could do the memory at the same time if necessary, but do you think for now I could get by just by upgrading these two? I can count on doing memory and the hard-drive at a future date.