Thanks to TechCrunch I was able to get in the Beta of a new online game called JamLegend (and you can get in the beta right now too, keep reading).
Taking a page right out of Frets on Fire, you are using your keyboard's F1-F5 keys as the frets and "Enter" to strum. While I'm a legend on plastic guitars for my console (throw ANY song and medium and I will 80% at least!), changing up to play on the keyboard actually took a few minutes to get adjusted to, but once I was in, that was all she wrote.
Wired writes: Activision's Guitar Hero and MTV/Harmonix' Rock Band have a new challenger waiting in the wings that plans to offer a free online game similar to Guitar Hero built on a social network that will allow people to compete against each other online.
