Honlai Technology is making a mini LCoS LED projector for the Apple iPhone and iPod.

The QingBar MP101 is an iPhone and iPod dock that has a small projector integrated. Like other docks you can recharge your Apple device when its docked.
The portable projector has a cool design, but you cannot expect too much in terms of image quality yet from these tiny projectors.
The Honlai QingBar MP101 features 10-15lumens, VGA resolution, and a screen size of 15" to 27" (50cm to 1m).

The Measurements of the mini iPhone projector are 76x102x54 mm.
More details on the Honlai site. Via Engadget. AVing has some photos of the Honlai iPhone projector in action.
My current favorite tiny projector comes from Foxconn though. The Foxconn Pico Projector one is not much bigger than a pack of cigarettes.