There's an awesome contest on Operation Awesome - a Mystery Agent Contest.
All you have to do is make a one line pitch for your MG or YA manuscript, and the winner will get the full attention of the whole manuscript from an agent! This ends September 30th or until 50 one-liners have been posted - whichever comes first. There are helpful links on the site if you don't know how to write an one-liner.
Go on and try it out! You have nothing to lose!
Ends: Already ended - the 50 spots filled up in no time.