Magic Shutter is a new iPhone app that will allow you to use your phone's camera to take long exposure images. For only $3, it's pretty sweet.

Slow shutter speed, long exposure shots allow you to do "light painting" and capture motion like cars whizzing down a highway at night with stunning effect. You'll need a tripod or a steady surface for your phone to rest on for this to work well, but if you feel like playing around with your phone's camera in a new way, this could be worth the cash.

Magic Shutter via Gadget Lab