I separated my shoulder.
No, not by biking, but in my basketball game last night. It popped out real nicely and popped back in shortly afterward. (My shoulder's pretty loose from a skiing wreck a few years ago.)
My wife thought I was nuts when I suited up this morning but I made it in just fine. The starts were a little tricky because I couldn't pull on the bar too much.
In any case, my regulare commuter bike had a flat and I didn't have time to change it so I road my Ti rocketship to work. I blazed along Santa Clara streets at warp speeds. The combo of the superlight road bike and strong, rested legs (from the weekend billygoat ride) really made for an exhilirating trip today, even with the shoulder problem!!