I film some of my riding, just to show the roads around here. Not because I commute or anything like that. I also enjoy watching clips on youtube for people who film their rides and commutes. I see the problems faced by them on a daily basis.
Its also an extra "insurance" policy against anything that might happen while you are on your bike. Today someone linked me to a video that I think to be a disgrace to cyclists everywhere.
This guy needs to start walking or taking a bus as he's a danger to himself, not only with his mouth, but with his cycling aswell.