pocket Guitar Hero
I played with this pocket Guitar Hero in the store. It's not the real deal by any means but it could be a good substitute when you're having a Guitar Hero withdrawal melt-down.
If you've never played Rock Band with these...you're missing out. the LED light system lights up while you play creating a stage show. Totally takes Rock Band to the next level :)
One of the most popular games of all time, a lot of my friends who don't like video games bought Xbox 360s just so they could play this at home. Tons of fun with groups!