Skype API

The Skype API documents a simple text based messaging protocol between clients and Skype. I believe we could develop a discovery and session management scheme for OSC based on Skype. A simple hack would be to use the chat message functions to send the agreed upon udp or tcp port and ip addresses for an "OSC" session.
Skype provides all the user name space management and authentication stuff for free and is becoming very widely adopted.

Another interesting tack would be to build an OSC PAL (Protocol Adaptation Layer) for the Skype API. This would allow users to create OSC servers for Skype functions.

oscgroups

OSCgroups does the session management (but not the security) in a light-weight manner which is pretty flexible.
http://www.audiomulch.com/~rossb/code/oscgroups/

I read about the Skype protocol when I implemented OSCgroups:
An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol

Layering on top of Skype would be nice for a number of reasons but I'm not sure what the overhead/latency would be.

Max Skype Object

Wojciech Kosma has written a Skype object for Max. See:

http://www.bek.no/Members/lossius/lostblog/611

I have a Beta version, including source code, which migh be of some interest.

mz