Check out "Hunting the Hidden Dimension", with a basic explanation of fractals, the Mandelbrot set, and a large collection of applications (blood vessels! forest health! textiles! eyeballs! heartbeats!). The website has neat stuff now, and you can watch the whole thing online starting Wednesday, October 29.
I love Nova. Especially Nova episodes about math. I show "The Proof", about Andrew Wiles' quest to prove Fermat's Last Theorem, to my classes when we have a down day. It gives them a taste of what professional mathematicians actually do all day. Also when they complain that a problem takes too long, I can remind them that Wiles kept at the same problem for seven years.