If you've yet to join the ranks of Xbox Live Gold status by subscribing to the service, you'll get a free trial this weekend. Starting today, Xbox Live Silver Members will be temporarily upgrade to Gold. This will give you access to online multiplayer funtions, and other perks that are normally afforded to subscribers. The free taste of the service comes in tandem with Microsoft's attempt to break into the Guiness Book of World Records with Kinect Sports. The record that they are going for: "Most People Running a Virtual 100m dash at one time". This could be a record that stands for ages, literally, since it is unlikely that anyone will ever beat this record, or ever attempt it again. Considering that there probably has never been a record attempt of this nature, you can be a part of history here people. If being part of history isn't your thing, perhaps the free avatar gear will pursuade you to participate. You'll net a free avatar award for your time.
I tried with one of my Silver accounts, and it wasn't on Gold so not sure if/when this is happening. (doesn't matter to me anyways since I have gold on my main acc.)