Can anybody tell me if there is a way to spoof the mac adress of my 360

thanks.

Highly doubt it.

absolutely there is, inside the 360 network control pannel there is an option there to change your mac address. Why it is there? not to sure, but the only reason i have ever used it was to easily configure a static ip address for my xbox 360.

Also i would like to note that this "Mac spoofing" doesn't give anonyminity to the 360 or user.

and just to note, it wont unban your console either