There's the daily poetry contest on lulu:
link While you're still a teen, u can enter the Teen Ink monthly contest:
link Similarly, Creative Communication is dedicated to student writers, and it has a poetry contest three times a year:
link A fair resource for poetry contests is the free newsletter provided door Winning Writers:
link Also Freelance Writing has a pretty current lijst of writing contests, many of which are for poetry:
link Finally, an excellent resource for poetry competitions in your area is your local library: just go up to the reference bureau and talk to a librarian there (not a clerk at the check-out desk!) about poetry contests.