Don't forget you have only until midnight July 20 (the midnight that separates it from Monday) to watch all three episodes of the 'Dr. Horrible's Sing-Along Blog' from Joss Whedon (Buffy, Angel, Firefly) for free at http://www.drhorrible.com. (You can still buy all three from iTunes for $2 each or $4 for the complete set.)

It stars Neil Patrick Harris as a wannabe supervillain caught in a love triangle with the girl from the laundromat he's crushing on and his nemesis, the "heroic" Captain Hammer (Nathan Fillion). Oh, and it features all three belting out songs co-written by Whedon, who proved he knows how to write a tune with the 'Buffy' musical, 'Once More, With Feeling.'

All three episodes are really good, though the first suffers from having to set up the premise. The second has the strongest songs, while the third makes you re-think everything you've seen over the entire 42-minute runtime. You also get cameos from familiar behind-the-scenes folks from 'Buffy,' including show-runner Marti Noxon and writer Drew Goddard (who recently wrote 'Cloverfield') and David Fury.