First came Dr. Horrible's Sing-Along Blog, Joss Whedon's musical miniseries that added a dose of rocket fuel to the already soaring world of online filmmaking. Now the Buffy the Vampire Slayer creator is planning to hit the Web again just as soon as he's finished his writing and directing duties on The Avengers. ''I really want to make something tiny. You know, get back on the Internet,'' Whedon says. ''Just something really home-baked.'' He's been developing an end-of-the-world project called Wastelanders with novelist and comics scribe Warren Ellis, which was postponed by The Avengers. When he does return to it, Whedon promises Wastelanders will be far different from the comedic tragedy of Dr. Horrible. ''I'll say this about it...there ain't no singing,'' he says, laughing. ''It's a dark piece, and I'm just like, 'Gosh, well, if I'm going to finance this and put it together, it's kind of dangerous.' It's not going to have a soundtrack album, it's not going to have all these revenue streams. It's going to be something that I put out there because I feel like I have to, and I don't have to rely on anybody else to let me.'' But as a TV creator and tentpole director, why bother with Internet shorts? ''Right now, it's the punk rock of filmmaking,'' Whedon says. ''And I want to be a part of that.''