Picasa Web AlbumsMore here.
See your photos arranged on a map, and show friends exactly where you took your best pictures. Simply type a location into the 'Place Taken' field when creating a new album, or refine a photo's placement using a drag-and-drop map.
Update 9/2/07: Google's Picasa image integration with both Google Maps and Google Earth doesn't work the way I'd thought it did. I'm not sure how it's supposed to work, I can't find any documentation. The one thing I see is that all images are not routinely available to the public even when the appropriate layers are enabled. As of 9/07 image display in Google Maps seems to barely work at all.