This one is for the travelers that bring their 360's, PS3/PSP, and their iPads to hotels.
First off if you don't have a laptop with you, you will have to call the hotel's wifi provider to authorize your device. Or have a friend do the last part, where you enter in the address and log in since its web based.
I'm going with a popular ISP, since they provide internet to hotels all across the U.S. (any other providers should be similar, if not call their support hotline). Something many people have gone through is having their wireless devices (PS3s, PSPs, Ipads and 360s) unable to load or get past the log in page.
This is the address that I get on my PS3 and PSP's when I try to log in, minus the details.
Look at the address bar in PS3, PSP, or iPad and get the information to fill in the blanks and enter the filled out address into your laptops address bar and hit enter, once it loads log in like you did to authorize the laptop. Refresh the browser on the device you wanted to activate and you should be logged in.
Now the 360 is a bit more tricky and if you don't have a laptop you won't be able to have a friend log you in. You'll need to get the MAC address from it and the IP as well after you attempted to connect to the wifi. The rest you'll have to get from the laptop, don't fret it should be in your history menu since I'm assuming you already logged in. The rest follows like before, post it in the address bar on the laptop, hit enter and log in like normal. Attempt to connect to xbox live and viola it should be online.
I spent hours upon hours trying to connect to a hotel's wireless with my game systems before giving up and calling tech support years ago and last week I look at the web address and I figured this out. This isn't a hack, its not illegal, think of it more as a remote starter for a car.