The OnLive Blog announces the promised closed beta testing of OnLive is now underway, offering the chance to try this cloud-based gaming service first-hand (thanks Kotaku). They are still collecting beta sign-ups, and here's word on testing:

When you sign up for OnLive Beta, you tell us some general information about your ISP, your computer configuration and your location. We use this information to organize Beta testers into test groups so that our engineering team can focus at different times on testing different situations. If you are a potential fit for a particular test group, we’ll send you an invitation email, asking you to run a detailed Performance Test on your network connection and your computer configuration. The results of the Performance Test will then feed back up to OnLive, and if you are a fit for a test group at some point during Beta, we’ll let you install the OnLive plug-in into your browser. Then, we’ll ask you to spend some time playing…um, I mean…testing games OnLive.