For those of you who are HALO players, Microsoft has started the sign-up for the beta:

http://halo3.com/index2.html

Requirements (straight from the linked page):

Please note that in order to register* for the beta, you must be 17 years or older and a resident of the 50 United States (includes District of Columbia) or Canada. If selected to participate, you must have access to the following:

- An Xbox 360 Pro console (includes hard-drive) or an Xbox 360 Core console with hard drive
- A valid Xbox Live Gold subscription
- A valid Microsoft. NET Passport account with a Xbox Live gamertag linked