Panoramio photo sharing website includes capabilities to put an X mark on Google Maps / Google Earth where you were standing when you took the photo. The site several years ago used to have URL links to member's personal KML files. KML stands for Keyhole Markup Language. The Panoramio site still has such capabilities, though the link to the personal KML seems to have vanished from the current Panoramio interface.

The URL syntax for locating the KML of a particular member is as follows:

Where the ###'s get swapped out for the particular user account number in the Panoramio site you wish to obtain the KML for.

Obtaining this, you may then download that KML file, open it in Google Earth, which adds the KML file to your "Places". Google Earth will then put a place mark with a thumbnail of the particular photo when ever you are browsing over an area the particular user has placed a photo place mark at... even if the particular photo was not selected for general distribution for the Panoramio layer within Google Earth.