On-screen and accelerometer controls work great for some mobile games, but other times you just want a real controller. Wikipad, the company behind the gaming-centric Wikipad tablet is introducing a new product called the Gamevice at CES. This is a split controller that expands and contracts to fit on your mobile device.
The Gamevice has what Wikipad calls a "flex bridge" design. Presumably the middle portion of the controller can be adjusted to snugly fit around your mobile device.