OnionCat creates a transparent IP layer on top of Tor's hidden services.
It transmits any kind of IP-based data transparently through the Tor
network on a location hidden basis.

You can think of it as a point-to-multipoint VPN between hidden services.

OnionCat is based on anonymizing transport layers like Tor. 

WWW: http://www.cypherpunk.at/onioncat/