We have featured a few of these iPhone 4 keyboard cases here at Geeky Gadgets, the latest one is the Kiano 4 which will add a slide out QWERTY keyboard to your iPhone 4.

It connects to your iPhone 4 via Bluetooth and it features a built in rechargeable Li-Ion battery which will give you up to five hours of continuous typing and up to 30 hours of standby.

The Kiano 4 iPhone 4 keyboard is available in black and white for $99 from iNature.

            

Source Gizmodo