Sorry to disagree, but there are several high-end systems that do precisely that. The blackhawk switcher is used with high-end presentations and can store hundreds of slides quite easily.
Another possibility is a projector with a smartcard chip in it. I would assume that this is unlikely since you have to purposefully load the slides onto the chip, but the low level of graphics on the presentation I saw lend themselves to a "chip presentation"
I think you mean smart media, such as a flashcard, the largest smartcard chips have nowhere near enough memory for a powerpoint presentation of any size.