i used a garmin virb camera on my bike for a while, it recorded a couple of near misses but if I'm honest i did nothing else with the footage other than watch it back and say "oh, that was close". They can be pretty expensive and if you're planning on using the footage to record rides, remember scenery etc then you'll need to spend time editing it which in my experience was a bit of a pain. Footage from the camera mounted on the bike can be pretty repetitive to watch as a viewer, think about helmet or chest mounts if you're looking to produce some decent images.
i stopped using it pretty quickly because I didn't think that it was really worth it. If you regularly ride in areas of heavy traffic and are concerned about having to evidence liability as a result of a crash I can see why you'd want one.
PS the club didn't have an issue with me using it, i had it on plenty of club rides and I wasn't the only person using one.
The following user(s) said Thank You: Chi kong Cham, Michelle Gallacher