I have recently discovered Waymarking and Geocaching. I like to take pictures, particularly when visiting local interesting landmarks, covered bridges, Etc. Waymarking is a natural extension of that. The main thing different, is adding a description and the location co-ordinates, from a GPS unit, or even a smartphone, using a free app.
http://www.waymarking.com Waymarking.com provides tools for you to catalog, mark and visit interesting and useful locations around the world.
http://www.geocaching.com/ Geocaching is a high-tech treasure hunting game played throughout the world by adventure seekers equipped with GPS devices. The basic idea is to locate hidden containers, called geocaches, outdoors and then share your experiences online.