The Glacial Lakes Motorcycle Club is open to the public. Anyone can join, no matter what you ride or where you live. GLMC puts on a few events each year for both on and off road motorcycles. They also operate a free public off road park in South Shore, SD (NE of Watertown).
The Global Geocache Game and the Greater Twin Cities Photo Tag Game are open only to members of advrider.com, which is free to join.