isn't it millions of on/off switches like and gates; [not Bill] and truth tables and that? - Related; cdr's & cdrw's are crystals and dyes that are opaqued/clear and red/blued by the laser for on/off state so i guess in chips it is similar but switches..
ooh, i was reading this recently. can't remember the link though :-( Flash memory has a silicon substrate layer (or something like that) that can be switched from conductive to non-conductive. This effect is so good that electrons (and therefore your data) doesn't leak through over a period of a decade. I'll post again when I find the damn link.