Short version: Joss Whedon has a musical web serial; go watch it.
Longer version: this is the video blog of Dr. Horrible (Neil Patrick Harris), a hapless evil genius who’s trying to perfect a freeze ray that will stop time long enough for him to figure out what to say to the pretty girl at the laundromat (Felicia Day). He’s also awaiting the results of his application to a league of evildoers. His escapades are mostly thwarted by Captain Hammer (Nathan Fillion), a beefy guy in a tight T-shirt and improbable gloves. This is a musical, so occasionally everyone just breaks into song… as you do when lamenting the imperfections of your freeze ray.
It goes without saying that it’s hilarious, but the music is surprisingly good.
The last act will be posted tomorrow. The whole thing will be available until midnight (not sure what time zone) Sunday, after which you’ll have to get all three parts on iTunes or wait for the DVD. Go forth and watch!