Jeff Beard at Law Tech Guru Blog has some good advice about watching out for fake wi-fi hotspots created by computer to computer ad hoc networks. Apparently this scheme is most commonly found at major airports. Jeff gives a great definition of these ad hoc networks as:

“Fake Wi-Fi hotspots and “man in the middle” attacks are nothing new. The key is that they are actually peer-to-peer or “ad hoc” wireless network connections — meaning that your laptop connects directly to someone else’s PC, not a wireless access point. That’s a major security no-no, as they can sniff your logins, passwords, and other confidential data you send through. They can also deposit some nasty items on your PC behind the scenes. Guess what happens when you connect to your company’s or firm’s network when you get back to the office?”

Jeff also points to a great article from Computerworld. In the article, the author provides instructions for users of both Windows XP and Vista on how to keep your computer from connecting to an ad hoc network.