This is a demo of the Bluetooth two player mode of Gem Speed on Android. I'm using a Samsung Captivate and Motorola Droid. At one point I mistakenly stated that the phones were already paired, (I was using my wife's Captivate instead of mine), which works out because you get to see the whole connection process. Once your phones have been paired, it's a lot faster; you can just click 'Remote' on one of them and select the other phone.
When playing the game, if you accidentally tap one of your opponent's gems, it will still disappear, helping out your opponent.