The Scientific American blog has a short piece on how stone tools have been an integral part of human evolution for the past 3.4 million years. It's mostly a series of links to some articles featured on the online features of the magazine, but it's accompanied by this nifty video of Kyle Brown knapping:
Clearly, someone's very impressed at 1:58, when he knocks off a big honking flake! All kidding aside, I always enjoy videos like this, that really focus on the piece being knapped and zoom appropriately. They really do a wonderful job of showing the hand-eye coordination involved in flintknapping, as well as how much slight hand motion, control and feeling around is involved in the act... it's not just randomly bashing rocks, folks! And though Brown doesn't use gloves or anything to protect his hands in this demo (though notice the pad on his legs), for any novice knapper reading this, remember, in lithics as in love, use protection!