Coin Operated Collectors Association 
COCA is a club for collectors of antique (pre-1951) coin operated slot machines,trade stimulators, arcade machines, vending machines and related collectibles.
http://www.coinopclub.org/Melvyn Wright's World of Vintage Slot Machines
Classic British Allwins and slot machines.
http://www.pennyslots.co.uk/
Liberty Belle Saloon in Reno
Saloon run by grandson of slot machine inventor. Interesting slot machines and liberty bell bookstore
http://www.libertybellereno.com/
Classic Amusements
Dedicated to the hobby of collecting vintage amusement machines from the late 1800s to the 1960s.
http://members.aol.com/pennyslot/
AntiqueSlots.Com
Buys, sells, and repairs mechanical slot machines, electromechanical pinball machines, trade stimulators, old penny arcade games, and most anything that is coin operated.
http://antiqueslots.com/
The Vintage Slot Machine Web Ring
A ring of web sites for vintage slot machine enthusiasts, pintables, jukeboxes, vending machines.
http://www.melright.com/slotring/
