GameKlip comes in 2 versions, a wired version and also a wireless version, you do have to install an app called Sixaxis Controller (can be found in the Google Play Market) to allow the controller to work on the smartphone but it brings a whole new way of playing those games you have on your phone, there is also a tablet version of GameKlip in the making too which will be released very soon.
This only appears to be out for Android smartphones at the moment but I am sure there will be a Apple variant along in the not to distant future.
To purchase the GameKlip head over to their website and purchase it from their online shop here.
The wireless version will set you back $15 plus P+P and the wired equivalent will set you back $23 plus P+P and all prices are in US$