Mark your calendars, avid Avatar fans. When director James Cameron presented 25 (!) minutes of his new epic 3D, sci-fi, futuristic flick at Comic-Con Thursday, he sent the audience of 6,000 into geek overdrive when he announced that August 21st, 2009 will henceforth be known as Avatar day. What does that mean for you? Twentieth Century Fox will wrangle as many 3D and IMAX theaters as possible across the globe to showcase a 15-minute sneak peek of the film. But they’re not done—other cool Avatar fare will be revealed, like video-game trailers. Just do us a fave—hold out on the costumes and shenanigans until the full film release. — amy kates