If you're a gamer who is interested in playing Bungie's latest (and final) Halo adventure, Halo: Reach, but you haven't yet purchased a copy, Microsoft has a great deal for you. Thousands of participants testing the next Xbox 360 update will receive a free copy of the game.

Major Nelson announced the exciting opportunity on his blog, where he says that the test is limited to U.S. residents, and Xbox Live Gold subscribers will be favored, though non-paying Silver users may still sign up. If you already own Reach or aren't interested in it, Major Nelson says that other (as of yet unnamed) rewards are possible.

Curiously, the post says the update test will "help us prepare for an updated Xbox 360 disc format." Microsoft has provided no details beyond this on what might be changing about the 360 disc format, so it's unclear what effect this will have (if any) on future Xbox 360 games.

If you live in the U.S. and want your chance at a free copy of Halo: Reach, head on over to the Microsoft Connect site to sign up.

[thanks to Joe for the tip]