If you've got a song stuck in your head, this is the place to get it out (or make it worse through repeated plays). Go to Songerize, select a song name, artist, and hit play. That's it. No confusing interface, no sign-in screen, no extraneous information, no ads.
It doesn't find everything--in my quick tests, it had about a 50% success ratio, and completely failed on PiL and Jane's Addiction. But it found just about every pop and classic rock radio title I could think of.(Thanks to Listening Post for the tip.)