The Day of the Doctor

Today is the day: the 50th anniversary of the airing of the first-ever episode of Doctor Who. The 50th anniversary special, "The Day of the Doctor," airs today at the same time in both the U.K. and the U.S. (correct me if I'm wrong, somebody, but I think that's the first time that's happened for an episode of the show itself) and stars Matt Smith as the current Doctor (though he's leaving the role as of this year's Christmas special, to be replaced by Peter Capaldi), David Tennant as his predecessor, John Hurt as a hitherto-unknown Doctor and some Daleks and Zygons and such.