Have you ever heard of cyclocross racing? It's kind of a weird (but brutal) sport, sort of a cross between mountain bike racing, road racing and steeplechase. You ride what is basically a beefed-up road bike with knobby tires around a course that is punctuated with stream crossings, sand pits, mud wallows and 18" hurdles, most of which force you to jump off of and carry your bike while running and then remount without slowing down. It's a fall/early-winter sport that was originally devised as a way to extend the bike racing season into the inclement months. It's really big in Europe (especially Belgium), and was popular long before the mountain bike was invented.
Anyway, it's gotten pretty popular here in Minnesota (there's a race every weekend day from now through the end of November), and I'm totally into it right now. Just did a race in Hudson, Wisconsin with my friends, Hans and Fred. Here's a shot of Fast Freddie and Dewey Dickey (yes, that's his real name) doing the stream crossing.