i just bought a 64mb memory card for 7 bucks used to carry my gamertag with me to other xbox's its easy and simple just put your gamer tag on the card then plug it in and you are good to go on any xbox.
i wouldnt do the harddrive thing that would pretty much make having 2 xboxes like having 1 and you just changing rooms with it also i doubt thats what you had in mind when you bought a 2nd one







