Poets & Writers is a free online fiction and poetry resource. They describe themselves as “the nation's largest nonprofit organization serving creative writers.” If you've got a story or poem you want to get published, I believe this is a good place to start.
I'm going to have a trawl around the site this week to see how it works, and to see if I can find some potential homes for my newest poems.
Have you used P&W? What did you think of it?