Set your countdown clocks. The "Halo: Reach" multiplayer beta, which is poised to be one of the biggest test events in entertainment history, kicks off in just four days. Among the millions of "Halo" fans eagerly anticipating the beta is actress Aisha Tyler. Available starting today is a video introduction to the beta starring the actress, viewable exclusively through the "Halo 3: ODST" game disc. Tyler walks through all of the exciting new game modes and offers her own tips and insider hints for each of the maps while showing off some life-size "Halo" weaponry. It's a fun introduction to the beta that no fan should miss.