Cross-platform, Easy-to-Use Local LAN Chat?

Ars-Gonzo asks: "I was at a conference last week, and had a surprising number of people connected to a peer-to-peer wireless LAN during the lectures. I saw several Mac users typing away during the lectures, and I found out later that they were using iChat's Rendezvous-based local chat to talk to each other. iChat's local subnet chatting functionality is supposedly based on Jabber, but I can't get a Jabber client (on Windows or Linux) to connect to iChat, locally. Has anyone seen any iChat compatible LAN-chat apps for a platform other than Mac?"