GLA (Guide to Literary Agents) has announced a contest! Submit the first 150 to 200 words of your middle grade or YA novel, and you could win:
(1) a critique by agent Jennifer Laughran of Andrea Brown Literary Agency
(2) a query critique
(3) books from Writer's Digest.
Contest details and instructions are available here.
There's a nice interview with Jennifer Laughran on Justine Larbalestier's blog.