RE: Don Smith Cessna T-50
Rich,
A guy in my fly fishing club uses one a lot to record his fishing trips. I'm pretty sure they are alos (at least some models) completely waterproof. He hs taped one on a pole and sticks it under water to record the fish while he's fighting it. And yes, the do record audio. He talks while he's fighting the fish or while csting. These appear to be approximately two inches square or close to that.
I"ll try to get a few links to some videos he has done and post them for you to see. Some of the filming seems to be wide angle shots while others appear to be normal views.
Joe