In the course of our project, we developed a client for the Open Archives Initiative (http://www.openarchives.org/) protocol. We put it into a separate package so that is usable in other projects as well.
The OAI spec allows "service providers" to harvest metadata from "data providers" (mostly academic institutions - collections of papers, theses, etcetera); the idea is that service providers add search facilities, etcetera. We will harvest OAI archives in our P2P network on special nodes that will listen for search queries and respond with matching records from the archives - the effect is that you publish the whole collection of an institution on the P2P network.
We will publish the package in SqueakSource later, in the meantime, just shout if you want the code.
Regards,
Cees