nah, thought about it, then got my old Mustek DV4000 out of the cupboard and gaffa taped it to the handlebars,
they are about £20 on ebay, take SD cards, I put a 2gb one in and it gave a 6 hour recording time, and has a Nokia phone battery for power,
only problem with sticking it on the handlebars is the video is very jumpy from bumps, helmet cams seem much more stable,