The GoPro Hero is moderately priced, easy to use, takes excellent-quality HD videos, and it (so far) is virtually indestructible. The Hero produces superb quality video. You can choose any variety of HD from 1080p/960p/720p at 30 or 60 fps (frames per second). The folks at GoPro claim a battery life of 2.5 hours; ours went almost three.
In addition to great video, the Hero also acts as a 5 megapixel still camera, but the lack of a viewfinder is somewhat limiting in that regard. You can set the still-photo feature up to take a series of photos at intervals of 2/5/10/30/60 seconds.