I'm looking into buying some additional RAM for my MBP in order to run vista in parallels coherence mode. At the moment i only have XP installed and it uses up almost all my memory when i run it alongside osx. I allocated 512mb ram, and i know at minimum to run vista i need 1gb free. If i upgrade my ram from 2gb to 4gb, would i be able to allocate more ram to parallels and run vista more smoothly along with osx? What are some of your configurations concerning memory on parallels to get vista running smoothly? or should i just not even waste my time with vista and keep xp running . that's what i'm leaning towards.