Facebook competitor ConnectU's co-founder twins, Cameron and Tyler Winklevoss, placed 6th in men's pair rowing in the 2008 Beijing Olympics. Their time was 7:05.58 on a 2,000-meter course. Australia won the gold with a time of 6:37.44.
How they find time to train and run a startup is beyond me.
The Winklevoss twins along with co-founder Divya Narendra are suing Facebook for stealing their idea. The three recruited Facebook founder Mark Zuckerburg during their time at Harvard.