I've got the factory pair of 512's and a second pair of 1GB for a total of 3GB. The issue is that I'm heavily using spaces which of course leads to lots of open programs but many are in use at once. Just last night I had the MiniDV camcorder hooked up transferring home movies via FW & iMovie, I had Toast 8 open and burning out a DL disc. I had Handbrake encoding one an existing movie and my second drive was ripping another movie. On top of that I was toggling between an excel spreadsheet, Mail and Safari while listen to some random music on iTunes. Needless to say, things were running pretty slow. Activity monitor said around ~1.5GB were in use, ~700MB were wired ~35MB were free and ~750MB were inactive. It also said there were a ton of page in and page outs and some like 65GB were being used by VM. Also, I noticed that when using finder in the coverflow view file/folder previews were taking some time to render. Today I saw that OWC has a pair of 2x2GB RAM for $159. I guess I'm wondering do I need more RAM and if so, how much?