Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
It re-initializes the directory services cache, which I find I have to do every now and then. Really once is more than I want to, because sometimes the directory services doesn't cache DNS properly, lord only knows what else is invalid in the DS Cache.

Using Snow Leopard 10.6.1.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.