Tropo has teamed up with Tethr to demonstrate a great new disaster relief communications platform at Google I/O in San Francisco today.

Tethr lets people get connected to each other and the Internet after a disaster. It’s a unique platform that lets people and organizations work together in difficult circumstances anywhere in the world whether they are online or offline.

Tropo adds voice to the Tethr platform and allows you to take your tropo.com applications on the road with you. When you add Phono with WebRTC into the mix, you get a system that allows calls into applications on Tethr or between users connected to the WiFi.

Today at Google I/O we’re showing Tethr, Tropo and Phono together with another capability. Using OpenBTS from Range Networks we are creating a small GSM mobile phone network inside of Moscone Center. You can make a phone call from Google Chrome to a regular mobile phone without any plugins or even configuration.

We think this has major implications for crisis response. Imagine a neighborhood of folks beset by a natural disaster that has destroyed the infrastructure around them. They plug Tethr into a car battery and are instantly connected to the people around them. They are no longer victims, but in control of their own destiny and are able to self-organize in a 20 mile radius.

For more information on Tethr, visit their website and sign up to be notified when you can get your own Tethr Box. If you’re at Google I/O today, come up to the Chrome Sandbox and play around with our revolutionary new tools.