[sukhbir]

By the word social (and now I think it can mean different things in different context), I meant that it is based on the concept that there is content which is common to a given 'social' group -- let's say with your friends who use Linux, you can use it to download a 10 GB distro. The set of those friends forms a social group that will participate in downloading the distro. You are right about the 'geo-aware' part but then there is no geo-awareness; it's all manual.

[18pfsmt]

I'm curious if you looked at Oneswarm[1], as it's built on the azureus platform (i.e. java) and utilizes PKI for authentication. It's not exactly lightweight, but I have setup ~30 friends, that I know and trust, on it in one tightly secure network.

For lightweight, on my router I have a transmission package (.opkg[2]) that handles files not available on my small network.

[1]http://oneswarm.org

[2]http://en.wikipedia.org/wiki/Opkg

EDIT: Running Openwrt (Backfire, 10.03) on Asus RT-N16