amenity's dashboard

I'm working on something like this too- or a global map where users could switch on and off multiple categories. There is a category tag in the georss feed, so I was thinking that maybe this could be done by making a Google map with a GGeoXML overlay on a static Wordpress page. Still not sure though. I've been playing with GeoMashup as well, and it has that capability built in...But no GeoRSS feed.