If you use [Dropbox](http://www.getdropbox.com), you might want to check out this [experimental 10.6 Snow Leopard build](http://forums.getdropbox.com/topic.php?id=11921&replies=27).
Using the previous release of Dropbox, I noticed that when sleeping and going to a different wifi network, then waking up, Dropbox would sometimes use 100% of the CPU and get stuck in a loop.
This new version claims to be more 10.6 compatible, and it does start up very quickly!