Publicly shared Wi-Fi could put your laptop & other wireless devices at risk.

With Wi-Fi access at airports, hotels, and aboard airplanes, business travelers don't have to look very hard for a wireless Internet connection.
But with these public wireless hotspots becoming more prevalent, in addition to more travelers using smart phones for Web access, are business travelers putting themselves at a security risk? The short answer, some technology security experts say, is yes. But they add that the use of Wi-Fi at these spots is no riskier than at a coffee shop.
"It's a shared medium, and if you can connect to it, someone else can connect to it and monitor your traffic," said Marty Linder, a senior member of the technical staff at the Carnegie Mellon Software Engineering Institute CERT/Coordination Center. "That has nothing to do with the security of the network. It's just the nature of the beast."

Link: http://www.cnn.com/2009/TRAVEL/business.travel/05/28/computer.security/index.html