One good way to keep up with the literature in a field is to track which new papers are citing seminal papers of the field. Each Friday, I get lots of citation alerts from ISI Web of Science, but often enough I see the same paper again and again (citing different papers that are on my watch list). So I set out to write an app that would take ISI's RSS feeds, coalesce them, and give them back to you. For example, in the screenshot one review paper is citing five of my tracked papers:
If you're using citation alerts from Web of Science, then give CiteWeb a try at citeweb.embl.de. If you find a bug, you can either comment here, or grab the source code and fix it. :-)
I started working on this to try out if Google App Engine was useful. It turned out that downloading many items from a remote host leads to time-outs from App Engine, so I ported the app to Django. The source code is released under the MIT License.