The helmet camera market has exploded in recent years, with the giant GoPro leading the charge. GoPro is constantly refining and improving their cameras, and it seems like they release a new product every six months or so. What really continues to set GoPro apart is the wide variety of mounts that they offer: all sorts of helmet mounts, chest mounts, sticky mounts, tripod mounts... just about anywhere you could think of mounting a camera, GoPro has a mount for you!
However, GoPro is by no means the only play in the market. While the now-defunct Contour used to be a big player, other companies are stepping up, such as Garmin, Sony, Drift, JVC, Rollei, and probably others.