Its a known fact that the Apple iPhones do not come with a stylus and conventional touchscreen styluses that come with others like HTC and TREO do not work on the iPhone. POGO is a special stylus that works on the capacitive touchscreen of the iPhone and the iPhone 3G.
The iPhone touchscreen is v sensitive to our skin (may be our body heat plays a role), So no plastic or metal styluses work on it. However the $20 Pogo Stylus works just fine and comes in 10 different colours!
This is an Old Gadget but launches at a new price now with a reduced pricing.