Last month I purchased a camera I could attached to my helmet. After only two days of wearing it on my commute I caught a near-hit in Harvard Square. For a more complete description of the near-event, read the full post.
I try very hard to be visible and predictable when I ride. In the video I took, I was passed by a car too closely, less than a foot away; I was planning on passing the pair of riders ahead of me but slowed down as I knew I couldn't make the maneuver. The cyclist right in front of me opted to pass the one in front of him without looking around to see if it was safe to do so, and without giving a signal. I could tell he was going to do this by his speed and slow drift leftward out of the bike lane - the car didn't budge, and the result is a very near-hit.
If you look carefully you can see the mirrors actually cross each other on the vertical plane. An inch from contact. It's possible that mirror-to-mirror contact wouldn't cause the cyclist to fall, though the whole situation could easily have been avoided by the car not trying to pass when it was unsafe to do so. Legally debatable: the cyclist should have right of way as he was ahead of the car; he should have signalled his intent, but his intent was also obvious.
The car driver had already broken the law when she passed me too closely. In Massachusetts the law requires a space of three feet, and she was less than one foot away when I was overtaken. The cyclist needs to be more careful how he rides, and the driver needs to recalculate her trade-off between getting to the next red light and endangering other road users.