Mobile phones could soon be helping in the aftermath of disasters by becoming an ad-hoc message passing network.
Computer scientist Thomas Wilhelm has developed software that lets data hop from phone to phone.
Messages sent via the application gradually migrates towards its intended target to keep communication going when other routes are closed.
The system could also help protesters in nations that routinely switch off networks to quell unrest.
Called Auto-BAHN, the project was unveiled at the DefCon hacker conference in Las Vegas in early August.
To pass messages the software uses the Bluetooth short-range radio technology and wi-fi that are ubiquitous on smartphones.
After a disaster, owners of phones that have the Auto-BAHN application can search for other users of it and pass on a message. Once sent, the message propagates across the network of other Auto-BAHN using phones until it gets to its intended target.
It could prove helpful during disasters and alert emergency services to the location of survivors.
Mr Wilhelm has produced an application that puts Auto-BAHN on Android phones and is working on one for the iPhone.
The applications are just to prove the concept works, he said, as he is trying to convince smartphone makers to have a similar system included as standard on their gadgets.