A semi-decent explanation, although it would probably be nice to explain that in organisms, the previous versions of certain structures were all used and weren't just hypothetical uses.

In this case, the speaker uses a mousetrap as a tie clip, but the mousetrap did not evolve as a tie clip. However, we have used the same idea of spring-loaded mechanisms as the hammers in breach-loading guns previously.

Christians don't believe in mousetraps.

Another good video is the same man, Ken Miller, discussing the Bacterial Flagellum, which is a favourite for Intelligent Designers to prove that irreducible complexity is infallible.

http://www.youtube.com/watch?v=K_HVrjKcvrU