The Kogeto Dot is an interesting little device. It's a lens that attaches to your iPhone 4 and allows you to shoot 360 degree panoramic video with the iPhone's little camera. Engadget tried it out, and they found it a little awkward -- you have to hold the iPhone perpendicular to the floor as you shoot, which means you can't actually see the screen unless you're holding it high above your head. But usability really isn't the emphasis here -- the lens comes with an app that will straighten out your video and even allow you to stream it right from the iPhone, so portability is the main driver in this case.
The company also has a standalone panoramic capture system already, so they've got some experience in the field to play off of, even if the actual iPhone implementation is a bit hacky. The Dot is currently available for preorder for US$98, pending actual production of the item. It'd be cool to see some video shot on location in this way, though for most panoramic shots, odds are you'd have gear built more specifically for the task.