Are their cameras that can clip onto things like glasses?

Me and a friend where wondering if their was cameras we could like buy at walmart or something that could clip on to his/my glasses.... He was wanting to know more cause he always where's his and we ussaly like to make videos and post then on YouTube but of course when something funny happens we don't have a camera... And for me, I wear contacts mostly but I think it'd be awesome! Go to school and recording when savanna bends over XD... Haha I might nOt but sounds awesome *wink*:)... If their are can you recommend like where you can buy them or what store its at. Maybe the prices :D