"The mesh concept, which is not new, is that instead of phone voice or data moving as it does now, from low-powered mobile devices to high-powered, fixed towers, phones (and possibly other radio-equipped devices) would act as a miniature cell towers and repeaters on their own, handling data transmission for nearby devices. So if you're calling someone across the street, chances are you might be able to connect to their device directly, or maybe in just one or two "hops," using other people's devices as the towers and repeaters of your ad-hoc network. Without cell towers, of course, there's no need for cellular carriers, no expensive private infrastructure to support, and no need for big recurring bills. A peer-to-peer mesh network is, in some cases, more robust than the traditional cellular infrastructure. It's certainly faster and cheaper to build." (http://www.shareable.net/blog/peep-wireless-proposes-a-peer-to-peer-cell-network)
- Ad-hoc Dark (roast) Network Travel Mug - Travel mug designed for creating ad-hoc “dark” networks for communication along a morning commute using an Arduino and an XBee module.
- Aidphone Flybox - box with inmarsat terminal, wifi access point, and GSM basestation to provide internet & mobile phone service to indy journalistsin crisis situations
- Ekiga: an open source SoftPhone, Video Conferencing and Instant Messenger application over the Internet.
- GNU Free Call is a new project to develop and deploy secure self-organized communication services worldwide for private use and for public administration. We use the open standard SIP protocol and GNU SIP Witch to create secured Peer-to-Peer Mesh Calling Networks
- Mesh Potato: a new device for providing low-cost telephony and Internet in areas where alternative access either doesn’t exist or is too expensive.
- Open BSC:  OpenBSC is a GSM network in a box software, implementing the minimal necessary parts to build a small, self-contained GSM network.
- Open BTS: OpenBTS is an open-source Unix application that uses the Universal Software Radio Peripheral (USRP) to present a GSM air interface ("Um") to standard GSM handset and uses the Asterisk® software PBX to connect calls. The combination of the ubiquitous GSM air interface with VoIP backhaul could form the basis of a new type of cellular network that could be deployed and operated at substantially lower cost than existing technologies in greenfields in the developing world.
- Open-Mesh , Open Mesh is different from other efforts to build local networks in that their direction is not the connection between different nodes separated by larger distance but the extension of existing internet coverage inside buildings, and between adjacent structures.
- OpenMesh Project: global project born after the Egyptian blackout
- Peep Wireless is proposing a peer-to-peer alternative to the hegemony of cell providers that could provide low-cost mobile connectivity to low-income populations.
- Pirate Box  is a self-contained mobile collaboration and file sharing device. Simply turn it on to transform any space into a free and open file sharing network.
- Ronja  - wireless networking device with range of 1.4km & communication speed of 10Mbps full duplex
- ROBIN  - open source mesh firmware that can technically run on any device that support Open WRT. ROBIN networks can be managed centrally through the use of dashboards like Surreal (http://surrealwifi.com) and Robin-Dash. forums here: http://robin.forumup.it/
- Serval  ; the only working mesh solution that uses off the shelf phones and off the shelf unlicensed spectrum and existing phone numbers, and can work with absolutely no infrastructure.
- Village Telco : The goal of the project is to render local telephony in developing countries to be so cheap as to be virtually free. Thanks to advances in Open Source telephony software and the dramatic decrease in the cost of wireless broadband technology, we think this is entirely possible.
Overview at P2P Telephony