Dream accessory for iPhone 4 is a tablet screen: you simply dock the iPhone4 on the back of the screen. The tablet will then show your iPhone UI on a bigger touch screen, similar to the iPad
Ladies and gentlemen, please welcome the iPod Touch younger brother, the iPad! Even though it's taller than its big brother, it suffers from the same preteen symptoms (no multitask, no flash), plus it doesn't even have a camera.