Lumu Light Meter
Pro photographers know that as great as the auto settings on modern cameras can be, nothing beats shooting with a real light meter. Now you can carry one with you everywhere with the Lumu Light Meter. This pint-sized gadget fits into the headphone jack of your iPhone, and uses a state-of-the-art digital light sensor to give you accurate exposure parameters whether you're shooting still photos, video, or even experimenting with a pinhole camera.