iPhone gaming controller

My ideal iPhone accessory! I hate digital buttons, this will be an immediate buy! Should we start a funding round on Kickstarter? :)

Update 2 I am already aware of iCade and Razer's Project Fiona. There are elements missing out from the shot (and from those devices for that matter) that will be made public once this idea advances to the next stage.

Thanks for the amazing response, keep them coming! :)