I've had this problem with my WiFi VoIP phone that I could not connect through authenticated hotspots because the phone lacks a browser. This is not about unathorized internet access, I use my T-mobile account, it's about being able to make legit calls with my phone.
So I figured out that if you spoof the phone's MAC ID with a laptop, connect and let the phone take over you can bypass the authentication step because the laptop takes care of it.
I don't carry my computer around but I do carry a Linux based Nokia N770 which works great for this kind of penetration hack.
These are Linux and Windows MAC ID faking instructions
http://www.skifactz.com/wifi/wifi_authenticated.htm for the purpose of connecting a browserless device to a public hotspot.