This is the HD Helmet Hero, a 1080P high definition action cam with a helmet mount and all the trimmings. Use it to scare pigeons, stalk rabbits, annoy clergymen and generally act off the macho in your blood. Takes SD cards and will store up to 2.5 hours of footage per charge, which should be enough for most weddings. $299.99.
Included are mounts for attaching the camera to three helmets and two pieces of gear or vehicles, as well as a head strap allowing you to wear the camera like a headlamp. You can also pull this strap over helmets for easy camera sharing between friends. One of the above mentioned helmet mounts is a lace-through strap-mount designed for vented helmets.
This would get in the way whilst in bed.