You can do an ipconfig /all at a dos prompt to get your MAC addy off your NIC. MAC addresses are spoofed with relative ease by someone wanting to get into your network. WEP, MAC filtering, change your SSID and turn broadcasting off, change the default IP range and disable DHCP. My router uses IP access lists for controlling wireless clients instead of MAC filtering. There are many ways to secure your WLAN. It will never be extremely secure when you are talking about micorwaves as the medium, but following the procedures listed by the board members here should give you some peace of mind.