Bandsintown's web facilities have gotten an overhaul recently, adding Pandora to its Last.fm account syncing, social features, streaming tweets and pictures from concerts as they happen, and the ability to track nearby concert venues in addition to artists and music types. The iPhone app, however, is the convenient tool for finding interesting live music when you're on the go, running through your iTunes tracks and using your location to pull picks from its impressive database of ticket providers and music venues.
Bandsintown's site and iPhone app are free to use and require an account sign-up. Editor's note: I feel compelled to mention this screenshot was taken from a friend's iPod, not my own music collection. Not that there's ... anything wrong with it.
Bandsintown