Plenty of WiFi routers have guest modes for visitors; some companies base their entire business models around them. Many of these devices are full of security holes, however, and the Electronic Frontier Foundation doesn't see that as acceptable in an era where widespread government surveillance is a fact of life. To fix this, it has posted a very early version of custom-built open router firmware that promises both easy access and security. While there is a guest mode, the new firmware (based on the existing CenoWRT) should patch common exploits that leave your home network vulnerable. It will even fetch signatures for updates through the anonymizing Tor network to prevent rogue code from posing as a necessary upgrade.