Photo sharing/community site Flickr launched a geotagging feature today that allows you to see where a photo was taken on a map.
Details at FlickrBlog.
Flickr geotagging interface is brilliant, but Yahoo Maps coverage for most of the World is very poor. If you prefer Google Maps for mapping your photos Panoramio, may be interesting for you. Btw, you can later watch the photos in Google Earth KML feed, a much better experience than web based maps.