Rip-Curl has come out with a goggle-camera combo for filming while you swim...sort of.
The Third Eye Goggle-Camera holds a small minicam that plugs into the analog input of a camcorder. It weighs about 60 grams, according to Rip-Curl specs, and is encased in shock-resistant aluminum and rubber.
As Gizmowatch points out, the casing is waterproof to 1 meter deep, but with the necessity for a camcorder connection, it's meant more for shallow water filming. You will still need your Fantasea casings for deep-sea photography or video recording.
The minicam has a high-resolution Sony CCD sensor, anti-fog screen, and interchangeable Essilor-BNL lenses for four different focus modes. Rip-Curl, however, does not specify what those modes actually are, or the megapixels of the CCD chip. The Third-Eye Goggle-Camera is available from Suneyes for about $702, and includes connection leads, microphone, battery housing, and a backpack to hold an accompanying camcorder.