"Dr. Horrible's Sing-Along Blog is a 43-minute musical film produced exclusively for Internet distribution. It tells the story of Dr. Horrible, the aspiring supervillain alter ego of Billy; Captain Hammer, his nemesis; and Penny, their mutual love interest. The movie was written by writer/director Joss Whedon, his brothers Zack Whedon (a television writer) and Jed Whedon (a composer), and Jed's fiancée, actress Maurissa Tancharoen." —the note I got.
If you enjoy the bizarre, then this is hilarious. I got clued in to this by
yaomtc earlier today.