Hi Folks

GNU Free Call is a new project to develop and deploy secure self-organized communication services worldwide for private use and for public administration.
It uses the open standard SIP protocol and GNU SIP Witch to create secured peer-to-peer mesh calling networks .

It may have interesting applications for truly secure, open & decentralized communications, which can stay up, in the event of a natural disaster etc.

http://planet.gnu.org/gnutelephony/?p=14

via http://news.ycombinator.com/item?id=2322881

Best,
ashish