I have a MBP, and plan to take long trip. Some motels have T-Mobile wireless. Is this something I can hook into? On the Apple discussions board, somebody posted that the Airport Extreme can double as a modem. How so? Assuming that I can hook up wireless to T-Mobile (or other wireless network), does the MBP automatically find the nearest wireless network or do I have to do something to find that network? When I get to an overnite where there is no internet access, what are my options othere than finding a local wireless access point? Thanks for the help!