Hi, my 2.66 ghz Quad Core Mac Pro has 6 gig's of memory. I always have several application's open at the same time. I've got Aperture 2 which is using 632 mb of memory but sometimes it goes over 1gb. Iphoto is using 300 mb, I've got firefox open, the New York Times Reader, Rhapsody's online player, Apple's email client, Itunes, etc. Do you guys think that 6gig's of memory is enough? Is more memory recommended? Would that 2 gig's of memory make a difference? Any info is greatly appreciated.