Shortly before I got rid of my Huffy BMX bike for my first "mountain bike" (if you could call it that) I was riding to a friends house a couple blocks away. I was weaving down the street, making large graceful deep turns as I rode. In the middle of one of those turns something happened, that something happened to the chain. The next thing I know the rear wheel is sliding one direction and I'm flying the other. Took most of the skin off the top of my left hand and still wear a few scars from that one.

Before that, on the same bike, riding up the street with a friend of mine running in front of me (BMX bike - riding fairly slow). I'm distracted by someone off to my right, about the same time my friend STOPPED directly in front of me. Ran smack into him, and I took the majority of the damage between the two of us. Worst part a) I tore a hole in my brand new jeans my parents had just got me for my birthday and b) it was right before a big neighborhood party and I was too banged up to enjoy it.