I came across a great open source software for geotagging your photos. GeoSetter is a freeware tool for Windows for showing and changing geo data of image files (e.g. images taken by digital cameras).
Geotagging is the process of embedding GPS coordinates into your photograph's EXIF metadata in the file. (Wikipedia Article)
Why would this be of interest to anyone?
Websites like Flickr or Panoramio not only allow you to upload your photos but also add an additional aspect to the social sharing of your photos by automatically tagging and dispaly them on world maps like Google Maps, Google Earth or Yahoo Maps. Recently while planning a trip to France, I found this feature very useful to see the actual location of other photographer's online photos right inside of Google Maps which allowed me to get an idea of places to consider for our itinery that offered great photo opportunities and sites to visit.