OC-Melbourne has posted a how-to article on how to change the MAC address of your Network Card.
We used Windows 98SE, Windows 2000 and Windows 2000 Server, Windows XP, RH Linux 6.2 and 7.1 as well as FreeBSD 4.3 in combination with two RealTek 8139c based NICs, a Realtek 8139b based NIC, an Intel 21143 (Tulip) based NIC, an Intel PRO/100+ NIC, and a RealTek 8029 NIC.Read more