I bought the £88 cheapo from
http://www.sports-camera.com/helmet_cameras.htm It works fine and gives a good picture quality for the money, the wide angle lens isn't to wide so doesn't distort the image to much, and it has a 1/4 inch tripod thread on the back so it is easy to connect it to suction cups, clamps or monopod to attach it to things or reach into places.(pretty standard for bullet cams I would think) I'll put up some footage if you want to see how it performs.