Spotify, Rdio, MOG, Grooveshark, etc... all have their strengths and weaknesses (Spotify, for example, is a great source for Norwegian black metal). The trouble is, it's neither fun nor easy to jump from app to app, web site to web site just to find what you're looking for. Music Smasher simplifies things by letting you search most of the big sources in online streaming tunes simultaneously. It trolls the four services mentioned earlier, as well as SoundCloud and Bandcamp. Well, it searches Grooveshark in theory, but every query we tried simply returned undefined results. Hit up the source to try it out for yourself.