iConcertCal might be one of the coolest things we have seen in a long time. It's is a program that runs off OSX (and Windows) and uses the music in your iTunes library to find concerts coming to your area. Then it adds them to a visualizer program that looks like a calendar in your iTunes.
In the About Us section of the website, iConcertCal states, "We are not a company and this is not a commercial venture. We are just two grad students in electrical engineering. We wrote this plug-in in our spare time because we were tired of missing concerts for our favorite bands and we figured other people probably are too. We are still working to improve iConcertCal, so if you have suggestions please send them along to us."
Sounds awesome right? The best part of all is that it's free!
Get it here: iConcertCal
Screenshot of iConcertCal: