wiredmikey writes "Wireless Internet routers used in homes and offices could be knitted together to provide a communications system for emergency responders if the mobile phone network fails, German scientists reported on Monday. In many countries, routers are so commonplace that they could be used by police and fire departments if cell towers and networks are down or overwhelmed by people caught up in an emergency, they say. This rich density means that an emergency network could piggyback on nearby routers, giving first responders access to the Internet and contact with their headquarters. The researchers suggest that routers incorporate an emergency 'switch' that responders can activate to set up a backup network, thus giving them a voice and data link through the Internet. This could be done quite easily without impeding users or intruding on their privacy, the study argues. Many routers already have a 'guest' mode, meaning a supplementary channel that allows visitors to use a home's Wi-Fi." This is a cool angle on mesh networking — reminds me of the emergency response capabilities of ham radio; if it sounds intriguing, remember that even sparse networks can make use of this kind of networking with the right antennas. Related: even without touching the hardware on your router, you can do some meshing around with Byzantium.