I like the google maps functionality of displaying photos on the map, linked to panoramio.com, it is very useful when you are looking for a place to spend your holiday.
loc.alize.us is a similar service which displays on a google map photos from flickr. You can chose to display photos from a specific user, or a specific place. What is appreciable is that you can see the tags and search by tag. I wish there was the possibility to use your flickr information, such as your contact list. It may be developed at a later time.
For example this is a search of my most prolific contact, cogdogblog (more than 18,000 public photos at this time!):
Photos need to be geotagged of course, and public. Here is a map of Paris tagged "architecture":
Now you can share maps of your own travels! I think I might share maps from time to time.