Pongs is a catch all term to designate those first generation consoles released in the 1970s which are based around the General Instruments AY-3-8500 chip. These consoles are distinguished from PC-50X consoles in the fact that the games are all built within the console.
Generally the games contained within any particular Pong console are variants on "Pong," i.e. Tennis, Hockey, Football, and other bat & ball type games. Later Pong consoles began to diversify with driving and light gun games.
By 1977 the market was saturated with literally hundreds of different Pong consoles. Demand began to wane for the machines as arcade games advanced with better graphics and different styles of games. The release of consoles with programmable ROM cartridges such as the the Fairchild Channel F and Atari 2600 made pong consoles obsolete overnight.
All the links below will not be active right away. In fact this page will probably never be "finished" as there are new Pong consoles discovered all the time.
It has been brought to my attention that some of the pictures appear with an "access restricted" error if viewed with Internet Explorer 6, however they work fine when viewed with Chrome or FireFox (which you should be using anyway.)