Now: XKCD helps you visualize the time of day all over the world

In Now, the latest XKCD cartoon, Randall Munroe provides a handy, continuously updated way to visualize the current time all over the world. I happen to know that Munroe is an inveterate long-distance driver who likes to pass the hours on the road by calling friends; I imagine that a wheel like this would be handy for helping him figure out which continent he should be searching for in his address-book in order to find conversational partners at any hour of day.