A search on didn't work for me yesterday, but today a search on
brought me here: http://trisquel.info/en/forum/ot-foss-skype-replacement so all is no lost.What I'm thinking about would be the equivalent of ham radio or citizens band radio, given that the wifi built into our computers can talk to other computers in the same household or workgroup already, and that there is enough signal strength to pick up other workgroups in the vicinity.
