A friend of the roomies played with one of our boxes to resolve some Vista performance issues he disliked.
* He disabled Readyboost and cutback Superfetch to boot-only. I still like Readyboost, but his other idea is good.
* There's some Windows Media services in Computer Management that auto-start to index MP3s and such. You can disable those: not sure that applies to 7, but helps in Vista.
* Windows Search & File Indexing services can be disabled.