I was riding on my favorite stretch of road today and noticed a horrible shimmy in the front end. Thinking it was time to get a new front tire (9000 mi), I continued on my route and didn't give it much more thought until I got home. I then started to inspect the remaining rubber on the front tire and holy s*#+ the front wheel was loose. My axle had come loose just enough to give the front end a wiggle. I loosened the two allen heads up front and found two full rotations of turn on the axle.
Everyone may want to check yours. It was a pretty scary feeling thinking of a great lean angle going bad.