OZ-Spy have great little CCD cubes,,, colour & sound,,, really good things, $200,,, we mount these under our visor on the helmets (out of the way for if,,, no sorry "When" we crash

But they need some sort of recording devise to plug into (like a video camera / handy cam, with an "AV In" plug (rare tho) panasonic used to make one but not sure what`s avaliable these days
so i use a JNC mulit media player/recorer to plug it into, shove it in my pocket & off we go,,, has good sized screen, button lock outs so you don`t bump them on/off when you don`t want to, & only about $400
there are quite a few Down hill mountain bike videos with my helmet cam footage involved
But there are water proof pencil type cameras avaliable now too,,, with battery & memory card already in them, strap it on & have a play (sounds kinky i know

) check out e-bay , they`re great cameras ,,, a friend of mine bought a couple for his race car (after he`d been using mine for years) so now i want one for when i go surfing

These ones are only about $200 all up, job done.