Most iPhone users like to think that their beloved devices can do pretty much anything, but if you really want to become the next Annie Leibovitz, I'm not sure if screwing this giant lens onto your phone will do the trick.
The Photojojo iPhone Telephoto lens magnifies the image up to 8X, which should give the phone plenty of reach, although I expect the speed will take a pretty big hit. Still, at only $35 I don't think anyone's expecting it to perform like a really serious lens.
The way it mounts however is pretty clever. Basically you have a special iPhone case that has built in mounting points for the lens, and for the included mini tripod. That's a whole lot easier that some of those kludge-like attachments we've seen before.
The iPhone Telephoto lens is available now for $35.