PS: Gnucleus uses already UDP similar to suggested above. It is called 'Gnucleus LAN edition' and works without using an external Gnutella host cache. A qoute from their homepage: "Gnucleus LAN edition is really working great at colleges around the world, if your college is blocking gnutella, I suggest setting up a private Gnucleus LAN, I can find just about anything here on my 200 person LAN. In Germany there's a college with over 600 people using Gnucleus LAN, and in Ontario I got an email from someone on a gnucleus LAN of over 1,200 users!"

Swabby, a documentation or comment would be nice.