mapufacture is a GeoRSS aggregator. Here you can layer multiple GeoRSS feeds from different sources into a single map, and search the database of GeoRSS feeds by keyword and location. Search results are themselves available as GeoRSS feeds.
So you’re welcome to check it out, and feedback! If you’re at XTech this week, come find me and I’ll give you a demo. And remember this is all under development, so consider it a working prototype.