just spitballing here? How about mashing up NPR story locations, so people can see recent NPR stories about events in their area?

alternatively, if you can find an accurate source of data on where FM and AM radio reach, and genre's they play, you could do a mashup with mapping software, so people going on long trips can put in types of music they like and know when and what to switch the radio to.

or create some sort of plugin for shoutcast that allows shoutcast broadcasters to have a map of where their listeners are and interesting related geo analytics.