Shrem wears a ring engraved with a code that gives him access to the electronic wallet on his computer. Friends tease him that a thief could cut off his finger to get the ring. “They started calling me four-finger Charlie,” he says.

As of April 2, there were about 250 wallets with more than $1 million worth of Bitcoins.

The number of Bitcoin millionaires, though, is uncertain—people can have more than one wallet.

Winklevii have $11 million worth:

http://pandawhale.com/post/19050/of-course-the-winkelvoss-twins-are-involved-in-bitcoin