For those moviegoers having trouble choosing between the supervillain escapades of The Dark Knight and the goofy pop ditties of Mamma Mia! this coming weekend, Joss Whedon ("Buffy," "Angel," Serenity) has squared the circle as only he can. Act I of his three-part web series "Dr. Horrible's Sing-Along Blog" launched today, and after several hours of crashed servers it seems to be up and running here. (It's also available from iTunes.)

Follow the exploits of Dr. Horrible (Neil Patrick Harris) as he works to be accepted by the Evil League of Evil and by Penny, the girl at the laundromat (Felicia Day), all the while dodging his super-nemesis, Captain Hammer (Nathan Fillion). The action sequences and effects aren't exactly state of the art, but "Dr. Horrible" is sure to boast the best songs of any superhero offering this summer, musical manna for those of us who still sigh happily at the thought of "Once More, with Feeling."

--Christopher Orr