If you can't catch Joss Whedon's absolutely fabulous Dr. Horrible by tonight (when it will vanish from free internet forever) do not despair!
It's going to be available for download for a few bucks on Itunes, and, AND, a DVD (with extras!) will soon be following. I am telling you now: It is worth every penny. Most especially if you are already a Joss Whedon fan.
Joss Whedon is pretty much my all-time hero, a-yup, it's true.