Bookcrossing
Read and release your books into the wild! tag your used books with a unique tracking number, then follow their travels through the world at bookcrossing, the world's biggest book club.
http://www.bookcrossing.com
Armchair Treasure Hunt
Armchair Treasure Hunt
http://www.treasureclub.net/
Degree Confluence Project
The degree confluence project contains photographs of the intersections of integer latitude and longitude degree lines.
http://www.confluence.org/
Earthcache
Earthcache
http://www.geosociety.org/earthcache/
GPS drawing
GPS drawing
http://www.gpsdrawing.com/projects.htm
Geocoins
Geocoins
http://www.geocoins.ca/
Stadsspelen met GPSenGSM
La mosca ontwikkelt citygames waarbij je met een gsm en een gps op avontuur trekt in de stad.
http://www.lamosca.be/