You can add an image or photo as an overlay in a kml-file. You need to do the following steps:

• Convert the image to png (24 bits) and make it transparant (75% or less).
• Upload the image uploaden to your site: /images/image.png.
• In Google Earth goto the right location
• Place an overlay on the map and use the url to the image on the site: http://yourdomain.com/images/image.png
• Save the folder in Google Earth as a kml
• Check with notepad if in the kml-file the url to the image is correct.
• Upload the kml-file to your site: /images/kml-file.kml
• Create an article and place {mosmap kml='http://yourdomain.com/images/kml-file.kml'}

Example:

{mosmap kml='http://tech.reumer.net/images/Op_de_Paap2.kml'}