Remember how Back To The Future Part II had a trailer for Back To The Future Part III during end credits? Well, Joss Whedon was such a fan of that move, he demanded the same thing of Captain America: The First Avenger. Instead of a cookie at the end of credits, as we've seen in previous Marvel movies, we get a full-fledged teaser trailer for The Avengers. If you can't wait until Friday to see it on the big screen, you can check out the Bootsy Collins version below.