I don't have a camcorder, so I figure I might as well get a go pro, so I can take it with me for biking. As far as I know, there are three places to best put it: helmet, handlebar, chest.

handlebar = rattling screen from the aluminum handlebar bouncing up and down
chest = different views from the hood vs aero positions
helmet = less helmet ventilation, heavier helmet

I'm leaning towards helmet, toward the front of it, because it offers more of a 1st person perspective. But I'm wondering what others think.