I have just purchased a Telescope lens for my iPhone.
The box comes with a special case for the iPhone with a mount for the telescope to slide onto. Also included is a blue lens cloth, a nice little tie to attach to the telescope so you don’t lose it and of course the telescopic lens.
The zoom is 6x optical and works well with the built in camera on the iPhone. The case fits my 3GS very nicely, however sometimes a steadier hand than mind is required to get the most out of it the telescopic lens.