Vista has been out in the wild just a little while now, but the goddamn OS has likely already started to fudge its pants. Here's one of those too obvious "Speed up your OS articles" by Extreme tech. It would be completely useless, except, it gets into the nitty gritty of the OS. Just because you've had enough time to let Vista fuck up your PC doesn't mean you've had enough time to learn its intricacies. Go read.
Speed Up Windows Vista [ExtremeTech]