Organizations

Antique Telescope Society
International organization of colleagues interested in antique astronomical telescopes, books, binoculars and related materials.
http://www.webari.com/oldscope/

Canadian Historical Microscopical Society
Mission is to bring together private (and institutional) collectors of antique (and modern) optical instruments with particular emphasis on microscopes.
http://www.geocities.com/CapeCanaveral/Hangar/5485/index.html

Scientific Instrument Society
Bringing together people with a specialist interest in scientific instruments, ranging from precious antiques to electronic devices only recently out of production.
http://www.sis.org.uk/