If you live in the US, clear anything you have in your calendar for March 31 through April 2, as it has been 100% confirmed that there will be a free weekend of Xbox Live Gold going on.
From Xbox.com:
Free Xbox Live® Gold Weekend, exclusively sponsored by Verizon. You get 72 hours of multiplayer gaming bliss as we grant every U.S. Xbox 360 gamer* Xbox Live Gold status for the entire weekend!
Not only that, but you have the chance to win some stuff, including Microsoft points. Verizon is giving away one million points to people, in bundles of 500 or so, to be used to purchase games in the Xbox Live Arcade.
Unfortunately, I am in Canada… Doubt this free weekend applies to me.