phonecards
(and others...)
 
Old test cards to check public phones...

  

Regular phone card (old model) 20 swiss franks (2 way insertion)

("switzerland is yours" is probably not the best translation compared to the
other language's text but perfect on what you could do with these cards,
respectively the public phones which used them...)
 

Chip card series (samples)

France telecom old model

New model

nice picture ; ) phonecard

MCI /Delta prepaid card