Chip cards

Chip cards come in a wide variety, and their contents seems to exert a strong attraction on many electronics enthusiasts. Disposable telephone cards (some of which have become collector's items!) are a great starting point for many experiments in manipulating the electronics contained in the plastic. Some experimenters have successfully turned expired phonecards into electronic ID cards for use in controlled-access systems. Others, many on the 'hackers' front, use them to find weak spots in systems which have been declared totally secure.