Google Earth is an amazing tool to visualize data, and over the years we've shown you dozens of examples of that -- everything from census data to Google Analytics to LIDAR, and almost everything inbetween.
Sightsmap is a neat project that creates a heatmap in Google Maps based on the number of photographs that have been submitted to Panoramio. To see how to build these kinds of maps yourself, Alexander Tchaikin has a great project that shows exactly how it's done. Even better, his project page includes a variety of KML files so you can play with the resulting data in Google Earth.
Alexander includes dozens of examples, and hopefully will inspire you to create some visualizations of your own. If you create anything noteworthy, please let us know about it and perhaps we'll feature it on here in a future post.
(via Google Maps Mania)