Walking past my brother playing Xbox 360 today, I noticed Microsoft are offering a AU$1 one month Gold Subscription fee, in an effort to engage Silver members (my brother mooches my Gold membership, so he's Silver). Still, it's a pretty good deal for anyone who hasn't checked out what Xbox Live Gold offers.
The deal gives you a Gold sub for one month, after which you'll be charged the usual monthly rate of $10.95. For a full price listing for the service, you can hit this link
It's also worth noting, for anyone on the fence about picking up either a 360 or PS3, Sony's online service is completely subscription free.