Public hotspots are a hacker's delight. The networks lack encryption precisely because they need to be open to all comers. Unless you use virtual private network (VPN) software, anyone can see all of your wireless Internet traffic, including passwords and e-mail messages. If you don't have access to VPN, the best free VPN software is Hotspot Shield from AnchorFree. Just download and install it, and your Web browser will display the screen pictured here. Click 'Run Hotspot Shield', and the app's protection will start.