NewPages Young Authors Guide has the most up-to-date and extensive list of publishing opportunities for young writers that I’ve found.
The ALPHA SF/F/H Workshop for Young Writers is for “enthusiastic, talented young writers who have a strong interest in science fiction, fantasy and/or horror and a passion for writing.” Ages 14-19, University of Pittsburgh’s Greensburg Campus, July 14-23, 2010, in conjunction with Pittsburgh’s science fiction convention, Confluence, July 23-25th. Application deadline: March 1, 2010.

One. More. Freaking. Year.
I’ve been working on a story for 2 months now. Super-mind-blowing-awesomepants.