Yes. Wear your helmet! Wear your helmet! Wear your helmet!
In the article Helmet saves man when truck runs over his head on CNN.com, Ryan Lipscomb, 26, says he was riding on a bike path in Madison, WI, when he came to an intersection. When he saw that a delivery truck was preparing to turn right in front of him, he jammed on his brakes, flipping his bike and throwing him in the path of the truck… which ran over his head.
The truck didn’t stop. Police initially weren’t sure whether to declare this a hit-and-run, as they weren’t sure the driver knew that someone was run over. Ummm… Can you imagine running over something as big as a head with a helmet on it and not thinking to check out what that might have been?
Anyway, the helmet obviously saved his head from damage.
Read the full article and see a picture of the guy and his helmet at the link above.