A timely BusinessWeek reality check; see the full article for some recommendations
You have an hour before your flight, so you log in to the Wi-Fi network at the airport. You look up some stock prices, check your e-mail, pay a couple of bills online, and surf a few Web sites. Has it occurred to you that curious or hostile eyes could be peering into your computer and your network? It pays to be paranoid.
Another option: avoid public wi-fi entirely and use a wide-area wireless broadband provider