Write a plugin for endo
David Chartier likes endo so much that he banished NetNewsWire from his dock. High praise, I think, and now you can make endo do even more cool stuff by writing your very own plugins for it.
endo ships with some pre-built plugins (one for Technorati and another for Flickr), but if you want to build your own you'll need to know some programming (namely Cocoa).