A couple of applications I’ve found and installed recently:
Magnetosphere: an iTunes visualisation plugin that’s too good to be true.
Coda: the new all-in-one web development app from Panic. An excellent app, sure to get even better with each release.
Yep: like iTunes for your PDF documents, incredibly useful; I now need to setup a workflow to scan all my mail upon receipt and store it in Yep.
Wesabe: a personal finance web-service that allows you to tag your bank statement entries, view graphs of your earning/spending habits and share your personal finance tips with other users based on your earning/spending habits.