First, be aware that any data you send or receive can be monitored by any other wireless user unless you are using a VPN, secure web browser (HTTPS) or other secured connection. This includes login information, account numbers, etc., so be sure that you use the secured option for webmail, on-line ordering, etc..

The other important precaution to take is to disable File and Printer sharing and Client for Microsoft Networks on your wireless adapter if you have them enabled. Not all public wireless hotspots use technology that prevents wireless client-to-client communication. This writer recently used the free wireless in the food court of Pittsburg's airport and found via a quick browse of My Network Places that the entire drives of numerous fellow wireless users were totally accessible. Both settings can be found in the wireless adapter's Network Properties.