Sorry for asking such a noob question, but I figured I might get more help posting it here than in the Newbie section.

Network cards come with MAC addresses, and some even allow you to change it. I was talking to that guy who told me that one of the best ways of securing a wireless network, is to allow connections based on the MAC address of the wifi cards.
But in that case, isn't it possible to eavesdrop on a connection, grab the MAC address and then change yours to that? Or do wifi cards not allow you to change your MAC address?

Apart from that and using WEP, any other suggestions on how to make a wireless network a bit more bulletproof?