well ive got 3 but when i added 870mb of readyboost it loads stuff like office much quicker now. is there a limit on how much it can use.
so, theoretically if you had say 250Mb ram you could include a 2-4gb external stick and could run vista, assuming the cpu and graphics was up to scratch and the usb stick is ready boost compatable
If you have 2 or more gb of ram its a waste of time.