Sound Art Recordings - Acoustic Mandolin music by Butch Baldassari and others.
Mandolin Cafe - All things mandolin - discussion board, builders listings, tablatures, etc.
Guild of American Luthiers - Stringed instrument makers guild.
Classical Mandolin Society of America - Organized to nurture the growth and assist those interested in pursuing the art of mandolin playing.
Association of Stringed Instrument Artisans - A trade organization dedicated to the field of stringed instrument making and repair.
Acoustical Society of America - All things acoustical.