The Philosophy of Biology links to an amazing story- you can recover water flea (Daphnia) eggs from the muck at the bottom of a lake, incubate them and get hatchlings. Even from 300 year old sediments! The scientist profiled, Charles Kerfoot, was able to document evolutionary changes in the Daphnia from different generations-- up to 3,000 generations' difference-- grown side-by-side. In epochs corresponding to a heavy predator burden, he hatched water fleas with tail spikes and helmets; and in epochs without many predators, the bulk of the eggs hatched lightly armored progeny.
Read the PoB link for a pep talk about the immense explanatory power of evolutionary biology, and the vigorous nature of scientific inquiry. Awesome!
UPDATE: This made me laugh: Don't forget to vote in the Intelligent Design poll over at BBspot. Vote twice!