Dr. Horrible’s Sing-Along Blog was a hit 3-part web series.  Then Dark Horse Comics brought the hilarious, musically-inclined story to the comic book world.  And now you can read Zack Whedon’s piece on the iPhone, iPod touch, and soon on the iPad.  Just as a refresher:

In this one-shot comic, Zack Whedon and artist Joelle Jones (Token) establish how a young, impressionable, but brilliant Dr. Horrible was drawn into a world of crime. Readers are reacquainted with the charming, brawny, crime-fighting superhero extraordinaire Captain Hammer when Dr. Horrible crosses paths with his greatest enemy in an all-out showdown of immeasurable proportions. Special guest appearances include Dr. Horrible’s love interest, Penny; his sidekick, Moist; and a meter man.

Though its comic form lacks the music it’s still a great read if you’re a fan of all things Horrible.  And though the iPhone format lacks features like zoom and tap-to-turn pages, the promise of comic book readers for the iPad is all the more exciting.