Much like cellphones have practically put land lines out of business, mobile devices are fast changing the way we sign onto the web when we’re on the go. And that includes when we're staying in hotels. While the hardware we carry into hotel rooms is changing seemingly from one month to the next, our demands free and reliable WiFi have not wavered a bit. And as more and more of us start to travel with cellphones, laptops and tablets, the call for free WiFi is more urgent than ever. Yet hotels around the world, especially those luxury ones, are still charging daily rates of $10 or more for WiFi. Worse, some are even double-dinging us for our mobile devices. So you better know the lay of the free hotel WiFi land before you book your room.