Hi Gang,
One feature of Vista and now 7 that I don't recall being discussed here is a feature that is built in to the aforementioned operating systems is Ready Boost. It was reviewed and bench-marked by every tech site and their dog in the first half 07 and then largely ignored as being useless for gaming as, well pick your favorite saying. Today a customer I am building a machine for saw my new flash drive and asked me about ready boost. I decided to give it a try again for gaming not expecting much. To my surprise it added 5-6 FPS running Crysis Warhead, I ran the benchmark 3 times, all to the same result. if you are not familiar with ready Boost, It acts to service random disk reads by acting as a disk cache and is 50-80 times faster at random reads than the standard hard drive, depending on the speed of the HDD and the flash drive. So if you are a few frames from being able to play that beloved game with settings on high, you might want to plug in a fast flash drive and see if it helps.
here is a tutorial on how to use Ready Boost if you are unfamiliar with it.
http://www.vista4beginners.com/ReadyBoost

Hope it helps somebody