Given that a cellphone case can easily run to $35, the iPhone Telephoto Lens is something of a bargain, combining as it does both a long, long lens, a case to hang it on, a mini-tripod to keep things steady, and a micro-fiber cloth to polish everything up.
It works like this: You slip the iPhone into the case (where it can be left, should you be a case kind of person) and then clip the lens on, over the iPhone's existing lens-hole. Photojojo, which sell the kit, says that it gives the equivalent view of a 500mm lens on a 35mm camera.
Focus is manual – yes, there's actually a focus ring. And while the quality isn't great (you can check the sample shots on the product page), it's a lot better than you'd get from a digital zoom. In fact, considering that almost every iPhone photo these days is destined for a thorough grungifying in either Instagram or Hipstamatic, the soft, not-so-sharp images should be perfect.
Also: Amazing for peeping-toms.
The iPhone Telephoto Lens kit is, as I said, $35, and comes in two models, one for iPhone 3 and one for iPhone 4.
The iPhone Telephoto Lens product page [Photojojo]
See Also: