These three writing competitions from Writer's Digest magazine are now accepting entries:
~ 4th Annual Pop Fiction Awards: Entries accepted in Romance, Mystery/Crime Fiction, Science Fiction/Fantasy, Thriller and Horror. Deadline: Nov. 3, 2008. Details here.
~ 4th Annual Writer's Digest Poetry Awards: Any style, as long as the poem has fewer than 33 lines. Deadline: Dec. 19, 2008. Details here.
~ 9th Annual Writer's Digest Short Short Story Competition: Fiction that's "bold, brilliant...but brief." Deadline: Dec. 1, 2008. Details here.