Dave Crocker and I chatted recently about reputation systems. Dave mentioned that one of the keys is to clearly define the community in which reputation applies. On the Jabber network, I think it might be most interesting to define not user reputation (too many users!) but server reputation. This could be done in a mostly automated fashion. Criteria might include:
As a result of factors like this, we could define an automated reputation scoring system for Jabber servers. Your server starts at zero and gets closer to 100 if you do the right things.
It's worth considering among our other weapons against the inevitable rise of spam on our network...