In the late 1980s and early 1990s, you weren't eating your candy properly unless you were eating it from a PEZ dispenser. We were a little late in catching on to them in America, though - they'd been available (and popular) in their native Germany since 1927. The name comes from what they used to contain - peppermints - which are known as 'pfeffermintz' in their home country. Rather than being a novelty, the original idea behind the tubes is that they would protect your candy from oxygen and touch damage until you were ready to eat them.
They started to become collectible when dispensers began to be released with the heads of famous cartoon, television and movie characters on them. The most obscure of these characters are the most wanted to complete people's collections. At the top of the tree is 'Astronaut B,' from the 1982 World's Fair - that's worth $32,000 all on its own!