Plugins for popular mail applications allowing the ability to learn/report spam messages to SpamAssassin via the spamd protocol right from your inbox.
This program has a great deal of potential, but is isn't quite there yet. The final bits need to be programmed in to finish it up. Once that is done, it will be great. 11/28/11 This appears to now be abandonware. Maybe someone will be able to take this over and finish it. I still think it has potential.