Ehi try this: on http://www.midomi.com/ you can sing or hum a melody and the site will search for it... returning the best matches and letting you hear the returned (musical) results!!!
Now, it's fun - even if the results are not always what expected!!! I tried with different melodies... but the site managed to get only "It's the end of the world as we know it" from REM - then went on maintenance.
The question: the problem is in the software or in my poor singing abilities? ;-)