Solo Synchronized SwimmingThe seemingly oxymoronic sport of solo synchronized swimming is just one of a gaggle of lost, generally unlamented activities you won't see at the 2012 Olympics in London.

Practiced above by U.S. Olympian Kristen Babb Sprague in Barcelona in 1992—solo synchronized swimming's third and last Olympic year—the discipline isn't as odd as it sounds. Technically speaking, it's the music, not other athletes, that the swimmers are supposed to be in sync with.

While the sport—still practiced competitively in other venues—does require tremendous flexibility and stamina, many viewed it as something of a joke.

"It's just sort of making pretty figures in the water," said Bill Mallon, a past president of the International Society of Olympic Historians. "Like floor exercises while you're floating—jumping, toes pointed, spins, smiling, waving your arms."

(Pictures: London Leaps Hurdles in Green Olympic Games Bid.)

—Kastalia Medrano

Photograph by Richard Mackson, Sports Illustrated/Getty Images