ShowComber is a tool that tells you when your favorite bands/comedians/writers/thinkers/whatever are in town. I built it because I keep missing good shows because I'm too lazy to read the papers, and I think this is a problem that the internet should have solved awhile ago.
Here are the steps: sign up for an account. Tell it who you'd like to see. Tell it where you are. ShowComber looks for events in your area containing the names on your list, and notifies you via web or RSS. It's a work in progress.