Updates of online papers in philosophy
Brian Weatherson has set up a weblog to track changes of online papers in philosophy, similar to my diffbot, but of course much more useful for other people.
It would actually be easy to create an even more useful tracking system, which would not only update itself automatically but also provide a flexible interface so that you could, for example, list all changes to Richard Heck's papers in the last 5 months. A possibility to search for papers on a specific topic would also be helpful. Maybe I'll think about setting up such a system when Brian gets bored with his manual updates.