S-Ranks...Hmmmm

[NetNomad]

You CAN put your friend's serial number/access key/password on your memory card and get online. However if Xbox works the way Gamecube does, you should only do this if you are ABSOLUTELY CERTAIN you will never activate your own account. Once you put a SN/AK/pass on your card, you CANNOT GET IT OFF unless you use an AR. I made this mistake, and by deleting the system file thinking that would fix it, I wiped my first four characters and had to re-make them. So use this option with caution.

Or, you could trade your friend something for one... OR, you know what? Take a new, blank memcard, put his SN/AK/pass on it and one character. Take that character online, clear cmode and get S-Rank... then take the weapon you get, move it to your real character, then delete the other one. It's a great solution.