Looking for a fun documentary on math? (Sorry, "maths" for you Brits.) The BBC's Story of Maths is a history of the growth of mathematics from its earliest origins to its present applications. My favorite parts are the early stuff -- math used by Babylonians and early Greeks, math in early farming, math in early trade, and so on -- you'll see a lot of that in this first episode. It's a four-episode series, each episode broken into six parts...just search YouTube for "story of maths" to find them all (or consult this YouTube playlist). Here's the first episode (part 1 first, other parts after the jump):

For more, check out this YouTube playlist.