On some of the pages of the website I've included .Google Earth .kmz files.  These files are used by Google Earth to show a particular view of the Google Earth image.  But in these files there are thumbnails of actual photographs that will show on the Google Earth image in the location at which they were taken!  This technology is called "geocoding".  It works by "tagging" a picture with the latitude and longitude of the picture's location.  The tag is part of the JPG header of the picture - it doesn't show in the picture's image.  The tag can be placed manually, using various programs including Picasa.  It can also be placed automatically from a GPS track of when the pictures were taken.  This means that you must be using a GPS when you take the pictures.  Fortunately, I do that most of the time when I'm biking or skating. 

T he GPS data comes from the Garmin Forerunner 301, which I wear on my wrist.  This downloads into a program called SportTracks, which allows displaying the route, elevation, distance, speed and heart rate as measured by the Forerunner.  It also allows creating a GPS log file called a .GPX file, which is in XML format.  A program called "Location Stamper", which is part of Microsoft's WWMX project, is used to match the times on the pictures with the times from the GPX file and "stamp" the pictures with the GPS location at the time the picture was taken (the clock on your camera has to be set to the GPS time).  This "geocodes" the picture.

Next you need to take the geocoded pictures and include them in a Google Earth .KMZ file.  Fortunately. Picasa version 2.5 and there after seem to do this for you.  Highlight the pictures in a Picasa album and use "Tools > Geotag > Export to Google Earth File" to create the file.  For anyone with Google Earth installed, clicking the file will open Google Earth and show the pictures on the earth image in the locations where they were taken.  Very cool, eh?