Dan Catt (of Geobloggers fame - now at Yahoo) talks about 3 hidden (less known) features of Flickr Maps.
Specifically, he outlines how to get photos at a location by a simple url:
http://www.flickr.com/map/Detroit
Flickr outputs proper Microformats geo for latitude & longitude.
And you can get a GeoRSS feed (more on this soon).