Sparkz released a pico projector dedicated to the iPhone/iPod Touch.
With a battery offering 2.5 hours working time, the device seems to be polyvalent. It comes with a tripod and different type of cables to adapt with several ports/devices. It supports video in 640x480 and 1024x768.
However, such projector will not be efficient in daylight conditions and its battery lifetime might be limited, if you only intend to use it alone, you might want to use LCD-based watches.
