I made a hat cam last year. My camera was a little heavy for the bill of the hat so I could only wear it for short stretches. I had an old mini tripod. I just took the top part of it off. I got an old baseball hat and drilled a hole in the bill and then screwed the tripod top on. The reason I used the tripod top was for adjustability.
i would def. recomend a gopro with the head band mount, especially for the hero3 (the newest model) its much smaller than the old hero's. its very light, small, very user friendly and when im wearing the headcam mount i will honestly forget i have it on. i just throw the head band over my hat. its very comfortable. if you have any questions about the camera just ask or pm me if you want
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paul if you got about 2 bills to blow you should buy a go pro camera, i used to have one that i wore when playing airsoft all the time and they take hd vids. they come with a head strap but all kinds of accessories can be bought for them like helmet mounts and waterproof cases and such. they really are a great head cam and can hold a ton of video cause it uses sd card storage so you can put up to i believe 8 gigs of memory into one. check out gopro.com and look on youtube for go pro vids so you can see the vid quality, also another great one that i havent personally used but have friends that use them are contour head cams they are also hd like go pro but instead of a forward facing square shape they are a small round tube that goes on the side of your head instead of the front like a go pro.each will run you about 2 to 250 and are well worth the investment in my opinion. wish i still had my go pro but i was hard for cash and sold it, probably be getting a new one for this season with my taxes