A couple months ago I mounted an inexpensive (~$140) 360 view camera to my helmet for my bike work commute. Here's some recent footage: https://youtu.be/aTTEEWxJImk
It works well and might one day capture an accident. I just need to remember to charge it. I wear it even when it is not charged because it seems cars are more cautious around me when they see the camera poking off the top of my helmet.