really and truely u only need to smac the pc u use to activate the the account the laptop can be any1's, it can be @ any house i doubt the cc records every nic that connects up to ther system. personally i believed the only time they record a nic is when u first use the activation disc to activate ur account the pc nic u use to set it up the account gets recorded.
some routers comes with with mac cloning, i know linsky diffinately have it on its setup page. have a poke around ur router and see, if it does just enable it and change the mac.