I use a Kodak Playsport ZX5 for things like this. I'm going to try and record my first trad kill with it. I'm going after a bear that I've run across here in the mountains.
I will post video for you guys when I finish it.
The camera records in 1080p quality. It's slim so you can put it in your pocket, waterproof (to 10ft), shock proof and, unlike the GoPro, it has a LCD on the back so you can frame your shots.
If you get a GoPro then you have to upgrade $75 for their LCD to put on the back of the camera.
The Kodak Playsport ZX5 cost about $100 at Wal-mart right now. A GoPro will cost you $250.