Extreme Ironing:

According to Wikipedia, it is “an extreme sport in which people take an ironing board to a remote location and iron a few items of clothing.” “EI supposedly combines the excitement of an extreme sport with the satisfaction of freshly ironed clothes.” Most importantly for our intelligently skeptical readers, “Though it seems a parody or hoax, many extreme ironers take their sport quite seriously.”

Thanks to my friend Claire Hill for the pointer.

UPDATE: Rick Hasen points to the NPR story on the subject.