I'm really thinking Tinc-VPN

[John Fields]

http://tinc-vpn.org/

Pros:

• It is a long running, mature, Open Source Project, that is still being maintained and improved.
  
• We can APT-GET it on bannanian
• Small executable and memory footprint
• Mesh networking capability fits exactly with connecting small-ish numbers of households (+1 support person, perhaps us...)
• More Mesh: doesn't require a hub+spoke config like OpenVPN to carry all traffic
• *Can* use the hub as MITM for route of last resort for locked down ISPs
• Can bridge Ethernet segments at Layer2.  Which definitely has its uses for us (Appletalk?).
• Simple to config, and remotely re-config
• Can produce GraphViz compatible typology maps (vector neato!)

Cons:

• Likes to tunnel via UDP, which can be blocked in residential ISPs
• Can bridge at Layer2 - killing DHCP servers if not careful.
• Others?

Alternatives: http://alternativeto.net/software/tinc-vpn/ 

Please read up and comment, especially on what they did to make ChaosVPN work atop tinc.