I've often wondered if peer-to-peer would be a good solution for blogging.
Given an application that can generate and maintain an RSS formatted XML file, it should be possible to publish its existence in a peer-to-peer network. I'm not suggesting adding a record to the graph, but rather the node's precense in a common graph would allow searching. The node would also need to register a unique, static name in the PNRP in order for others to be able to find the node again.
Search requests would be published as records to the graph with a short time-to-live (short enough that it couldn't propagate to all nodes in a large network). Any peer close enough to the originator would see this search request and compare its data to the request.
If there is a match, they could open a direct connection to the originator and send a quick response. Its unclear if this would overload the originator. The results could be arranged for presentation. The originator could then decide if they wanted to look at the full blog of each responder or subscribe for any changes or new blog entries from the responder. The static name in the PNRP is needed in order to allow the originator to contact the responder at a later date (if they available).
Blogging via peer-to-peer would allow anyone from their desktop to start blogging. No need for a web-site and no need for a central search engine.
Opinions are welcomed.