usually you can't upgrade the vid card from laptops. You could always take it to one of the local places (and don't go to any big shop which just sell computers, they probably don't know crap about computers) and ask them if it's possible to get a new vid card for your laptop.
The answer will probably be no, but it's still worth a try.
if you have vista, you would benefit because vista loves memory, but if you have xp, all that memory would actually slow the computer becuase it would be hard for stuff to be found in all that space.