I've always raved about the iCade cabinet for the iPad. I simply love mine. See my earlier posts on it. Now, ION, has made the iCade Jr. specifically designed for smartphones. Advertised for the iPhone 4 and previous iPod touches, this retro game controller/dock/cabinet also works with some Android phones and the iPhone 5 (with caveats).
For comparison, here it is next to the full sized iCade (for iPad and tablet).
It works awesome just as a stylish desktop dock accessory. You can route a USB charging/data cable underneath and have it simply sit on your desk.
The operation is very simple. This is a bluetooth device and all you need to do is pair it with your phone. There are games that are compatible and designed to work with the iCade controller. ION has a list of games that are compatible with the controller.
As I said earlier, this device works with other phones beside the iPhone 3GS/4/4S. You can use it with the iPhone 5 and other smartphones (of similar dimensions) by simply flipping back the top cover. It is not as pretty as an enclosed case but it works. If you are on Android, this dock may only work with phones with similar width dimensions as an iPhone. Moreover, the only supported iCade game app I know for Android is MAME4ALL.
Here it is with the iPhone 5 running some MidWay arcade classic games, Defender.
It is also designed to work in landscape mode. Here I have Namco's arcade versions of Galaga and Pacman.
And if you have MAME4ALL installed, you can play hundreds of retro mame games as well.
I gotta say, after a few minutes of playing with it, it is one cool retro toy to have around. This is great for old phones you have lying around that you don't use anymore. I plan to either use my old iPhone 4 or HTC Droid Incredible (fits perfectly).
Link: ThinkGeek's iCade Jr Product Page.