International Stereoscopic Union
The ISU (International Stereoscopic Union) was founded in 1975 and is the only international 3D association in the world. The ISU is a club of individual 3D enthusiasts as well as a club of stereo clubs. The ISU's members currently number more than 1,000 and come from over 40 countries world-wide. Membership is really affordable at 20 $/year.
The quarterly Journal of the ISU, Stereoscopy - the publication of 3D image-makers, is circulated to all ISU members. Apart from tuition in 3D photographic techniques, the Journal carries information and articles from around the world on new equipment, literature and all manner of 3D related subjects. The journal is printed in full color with hi-res pictures. check here.
The ISU president is Mr. Gert-Jan Wolkers; the ISU is represented by its treasurer and webmaster, Alexander Klein.