Forget about Jabber. I think it would be better to go with Telepathy. Daniele [0] is working on "Telepathy Tubes and File Transfer in KDE", and it would be a lot better to support multiple protocols via Telepathy instead just supporting Jabber. Once his project is complete we should be able to export a Dbus interface to other contacts, so that greatly simplifies the problem of how to connect/transfer stuff between 2 machines.