I live in OR and we have this quirky set of laws that I am seriously thinking of taking advantage of. On roads with speed limits in excess of 35 mph and no formal bike lane, a motor vehicle must give a bicyclist "room to fall" when passing. Naturally, this law is unenforced. In fact, even when unsafe passing results in death our local sheriff will not even cite the motorist. However, our vehicle code also allows bicyclists, with the obligatory assistance of law enforcement, to have a citation issued and act as the "prosecutor" in traffic court.
Obviously, it would help to have a bit of evidence. I am thinking of mounting a helmet cam (probably not on the helmet, though) to document the illegal passing. Does anyone have any experience with this? I looked at the GoPro HD Hero online and it looks like it might work. However, I couldn't tell if it would be able to pick up the needed details, which are a view that would be convincing that the motorist was within 7 feet, license plate and some look at the driver.
If I am going to tilt at windmills I would like at least even odds at winning.