Once upon a time, before zoom lenses were invented, movie and TV cameras had three lenses that the user could choose between, using a Lazy Susan-type arrangement to swivel them into place - you wanted to go wide, you'd swing in the wide-angle lens, if you needed a close-up, you'd swing in the telephoto. Well, in the spirit of everything old being new again, the iPhone Lens Dial now offers the same functionality for Apple's iconic smartphone.

The iPhone Lens Dial features 0.7x wide angle, 0.33x fisheye and 1.5x telephoto lenses, all made from optical-quality coated glass. The dial is mounted on an aircraft-grade aluminum case, that slips over an iPhone. The phone's camera lens lines up with a hole in that case, which each of the lenses sit over when they're moved into place.

The case also has two threaded tripod-mount holes (one on the bottom and one on one side) for taking photos in portrait or landscape format.

Whereas other similar devices such as Holga's Lens and Filter Wheel are marketed more as novelties, the iPhone Lens Dial is apparently aimed at serious use - at least, that's what its US$249 price would seem to indicate. It's available on Photojojo, which also sells a tiny-but-decent Fisheye, Macro, Wide Angle and Telephoto Phone Lens combo for $49.