If you are a fanboy of Halo series, then you need to mark May 16th because the much anticipated multiplayer Beta for Halo III is coming on the day that will run until June 6th.

To participate in the beta, you need either a specially marked copy of Crackdown that has a Halo III Beta sticker on them or if you are so lucky person out of thousands of participants to have your name in a the beta participants list compiled by Bungie.
Gold Xbox Live membership is another fundamental requirement that you must have because it is required to download the content as it is out.
In addition, three maps will be made available named Valhalla, High Ground and Snowbound that will only be playable using Matchmaking. The game developer Bungie is providing a chance to test out new vehicles and weaponry. This isn't end point, there is still plenty of undisclosed things that will be made public at the time of its release.
I hope you'll be the one out of thousands to get a chance to participate in the Beta and don't forget to share your experience here.
Via: news.com