my macbook has 2gb and i definitely use it all. i could use 16gb if it were mainstream enough... as soon as i even start to run my virtual windows machine the ram is full, and it uses at least a few 100 megs of swap space most/all of the time...

i bet it would be faster with 4 gigs, which seems to be the mainstream now. i can get a $5-600 laptop with 4gb.