If you guys aren't familiar with the program Shazam, you definitely need to be. Imagine this scenario: You're in your car, hear a great unknown song on the radio and have no idea where to look to hear more from the greatest unknown artist of all time.
Instead of digging through station logs, Shazam is an app that 'listens' to the song and quickly identifies its artist, song name, and album. In fact, it one ups similar music recognition programs by offering a link to the Amazon MP3 Store and Youtube Videos. If Shazam on Android works like its sister on the iPhone, this will be one of the easiest and most useful apps to date.