Sure, you could spend heaps of money on a fancy waterproof case for your camera, but why would you take that risk when Photojojo's selling a $35 digicam that shoots both photos and video, and can dive to 100ft? [Photojojo]
I have used this camera when Scuba diving. I affectionately refer to it as "shittycam". You get what you pay for, and I don't mean image quality (don't worry, it is absolutely awful), but you can't actually turn the camera ON below 35 feet. The pressure inside the case is too great to even push the power button. Cool, you can just turn it on before hand right and leave it on? Sure. The shutter buttons works when you are deep. Oh wait, 30 seconds of inactivity = sleep mode! I have had many dives where we went to 60-80 ft immediately... oops! no pictures for this dive!
Battery life is psychotic. Sometimes brand new batteries will last a few days, sometimes just 5 minutes. I don't think it actually knows how much battery life is left and just uses a random number generator to determine battery life remaining. When it says the batteries are dead, turn it on again and you are magically at half battery capacity. what.
Shutter speed is super slow, you have to stay still for about 3 seconds to have a clear shot. That's ok because sea creatures usually like to stick around and wait for you while you fumble with your camera.
Either way, it is only $30. The next step up is $250 ish for a gopro, or $500 for a housing for my olympus e-pl1.