Yes, I know, I spoof MAC addresses myself for certain purposes, but I believe that if someone really wants to get into your network that badly, they'll do it regardless. MAC filtering is fine for preventing the casual opportunist or messing kid in the apartment next door chancing their arm and trying to find some handy MP3s or ripped films. At the end of the day, it's a trade-off. If you really have precious information you can't risk anyone getting hold of, don't connect to any network.
