
I am currently in Boston and as you can see on the screenshot, the number of wireless networks visible from within a hotel room is higher than you may have ever expected. Some of these networks are not encrypted by WEP or WPA but they ask you to log on on a website. Some others are just open to the public and do not require any authentication at all.
What I am concerned about is that the WiFi standard 802.11b is limited to a very small band of frequencies. In fact, when choosing any channel between 1 and 11 you choose between overlapping channels. Without overlapping, you have just three fequencies to use.