First of all, you never know in advance if a hotel is going to have an internet connection or not. On their web pages they will tell you that there are *color* televisions in the room, that hairdriers are available and so on - but nothing about internet.
And if you call and ask, they will either not understand the question or simply reply "yes". But a "yes" might just as well mean that they have a "dataport" at the back of the telephone in the room so you can connect your laptop using its built in modem...
Once you arrive, you ask about wifi during checkin and - if you're lucky - they will tell you that WiFi is available ... for 30 euros/dollars per day. Yes, really, this is the price here at Holiday Inn in Cannes, France today: 30 euros for 24 hours using Hubtelecom. Fortunatelly, a single Orange hotspot was also within range, offering 24 hours internet access for "only" 9.90 euros.
Ok, you protest but you know you'll cough it up since, well, internet access is invaluable (and GSM/3G roming charges are even more expensive so you can't rely on tethering your cell phone either).
You enter your room, take out your laptop and realize there are no electrical plugs anywhere. Eventually, after crawling around on all four underneath a desk where the rug has been poorly vacuumed for a decade, you find that one plug that the desk lamp uses.
Finally you get around to actually start using your expensive internet connection. You log in and start using the net. Then you take out your WiFi enabled smartphone to make use of WiFi and avoid those expensive roaming charges for data - but that won't work. That expensive internet connection works only with one device, the one you used to log in. And what about that WiFi enabled digital camera that is now filled with travel photos and would need to be uploaded? No luck. You would need to buy three WiFi connections in parallell for a total of 90 euros per day. And if there are two of you, that makes six devices. Right now, I'm sitting in this Holliday Inn room with two laptops, two iPhones and two WiFi enabled cameras - and the hotel offered a 30 euros a day WiFi connection that can only be used by one device.
I have been in this situation before, many times, so come equpied. I'm now carrying the Asus "Portable Wireless Access Point" WL-330gE. A small USB powered external box with two WiFi devices: one is a client that connects to the hotel WiFi and the other is a base station that "forwards" the internet connection it has aquired to all of your devices. Since it uses NAT (Network Address Translation), the hotel WiFi hotspot will only see the Asus device and not all of your different devices.
You connect the USB power cable to the Asus box and now you will be able to see a new WiFi base station with whatever name you have given it. You connect your laptop to the asus device and go to 192.168.1.220 (its default ip) and you see a web based admin interface where the Asus device lists all external WiFi base stations it can see. You select the hotel WiFi network and the Asus will then connect to it and forward it to your laptop and all your other devices that connect to the Asus. You can, and should of course, configure the Asus to provide password protected access to your devices so that only your own devices can make use of it and not the entire neighbourhood.
Sharing a connection like this might be agains the licens agreement with some providers and in that case you should of course respect that agreement and pay 180 euros a day for your hotel internet connection...
Carl, This is very useful. You don't mention it explicitly, but I assume you select the "gateway" mode on the Asus 330gE. I will try it using the current Asus Model ASUS WL-330N3G. Many thanks, GRTMan.
What if you dont have laptop . you carry only ipads and iphones or android devices.