Haha not sure how you make a helmet cam.. but i can tell you that its worth buying one. Theres tons on Ebay for good prices if you're looking for lower cost alternatives, and if you want a more functional high end helmet cam check out theVIO POV.
theres other tuts on youtube but thats the easiest. The link you gave me didn't open for some reason so i'm just assuming you have a similar camera and helmet to whats in that video.
do not do that to your helmet. that will make the helmet break so much easyer on impact and you will get hurt easyer. just spend the money an a real helmet cam and save your head
glen plake in blizzard of AHHHHHS wears one. he has a helmet with a huge camera on one side, huge battery on the other side. the footage came out nice.