The 48 Hour Film Project is a long-running, widely covered guerrilla filmmaking contest that challenges people in cities around the world to make a halfway decent movie in two days. The contest recently added a machinima arm, and well-known Second Life machinimator Chantal Harvey is producing it. Along with Second Life, you can make machinima entries in World of Warcraft, Twinity, Half-Life, Moviestorm, iClone, the Movies, Grand Theft Auto, and more. "All rights have to be owned, and all has to be shot in real time, during the 48 hours of the contest," Chantal tells me. "Winning machinima will be screened at Filmapalooza Festival, and the 10 best films from that festival go to Cannes."
Go here for all the rules and registration page. Entry fee is $48, which may seem steep, but is actually much less than the fee you'd pay to enter a real world film in the contest. Plus I'll be covering the winners/runners up here!
Update, 8/19: In case you needed even more incentive, Chantal adds that the winning machinimas will be screened at the next Miami International Film Festival. Which is a perfect fit, because a lot of folks in Miami already look like avatars.