I have a Contour and have experimented with helmet mounting, handlebar mounting and head tube mounting. Of the three I prefer the head tube. Helmet mounting is nice in that the camera sees whatever you are looking at. This also means that when you tilt your head down you see nothing but the pavement below you. I found that I didn't like the constant motion of the camera mounted on my head, but as always, YMMV. The handlebar mount wasn't bad, but the bars amplify any road vibration and cause a bit of buzz, especially on tar and gravel roads. And while the horizon line remains relatively constant, the view tends to sway from side to side a tiny bit with my pedaling motion. I know, I know, smooth out my pedal stroke. :-) The head tube mount is the steadiest of all, at least for me. I don't get the subtle vibrations like I do from the handlebar and any movement from pedaling is greatly reduced. The only thing I dislike about mounting on the the head tube is that I always see the top of my tire and the bottom of my brake levers. But the forward view is great.

Cheers!
K