QUOTE(EX0S @ Aug 8 2005, 02:48 AM)

mac address?
Your MAC address is like a fingerprint of your NIC. it's composed of two part.
part 1 : 16 bits (If I remember right) identifying the manufacturer of the card, + another 16 bits identifying your card itself.
So basically if I have your Mac address, I can locate / identify you...
you might google ARP and "mac address spoofing' if you wish to learn more..