Acronym for People Can't Memorise Computer Industry Acronyms.
Ain't it true?
More boringly, stands for Personal Computer Memory Card International Association.
These are the credit-card-sized cards that can be inserted into most laptops (and several desktop) computers. These are now known as "PC Cards" as it is easier to remember.
Some examples of pc cards include network card, firewire card and CompactFlash reader cards.