I register my iPhone and use MyWi (from the Cydia App Store) to rebroadcast the wifi signal. It can create a virtual AP and NAT the signal. You can even use a PPTP VPN once the iPhone is connected to hide what you doing a bit more or to fill the room with a virtual US connection. Just make sure you use the wifi only mode or you could have a rude surprise at the end of the month. I like this in foreign hotels because it means I can make VOIP calls throughout the hotel.