Hero, a question like this will get a more enthusiastic response if you post in the Tech Issues & Bugs forum (<-linky).
This forum's more for in-game questions like "at what level can I get a cape", while more of the real hard-core tech heads lurk in the other forum.
Video card memory is soldered onto the video card itself. It's not like going from DDR/DDR2/DDR3, where you have to put it in yourself. If you go from (say) your 8800 to an nVidia 460, the memory and everything else the card needs is already there - just need a mainboard with an open expansion slot of the right sort and (depending on card) the proper power leads.
(Looking at it another way, it's like having a car with a v6 and wanting to buy a new one with a V8 - you don't have to do anything for the V8 but buy the car.)
Thanks and thanks 
I'm planning on doing some upgrades to my comp pretty soon, especially to take advantage of the ultra mode that I currently don't get to use. The problem? I'm pretty clueless when it comes to the hardware inside the computer.
I'm thinking of a new video card since mine is more than 3 years old. I have an NVIDIA GeForce 8600 GTS, with 256MB GDDR3 of memory. I'm looking in the $250, but I see that most for around that price are 1GB GDDR5. I don't know enough: can I switch from 3 to 5?
I have 4GB of RAM, and my processor is Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz.
Any Input?
Thanks,
@Chrichton - Victory