My favorite on the opposite end, is a random bit
stream produced by
using the pulses from a geiger counter (and associated radioactive
material) to clock a long shift register. It's well-discussed, but I'm
not sure anyone ever produced one.
I *think* some military crypto gear did things link this, but I am not
sure.
I know that AT&T once marketted a true random bitstream chip using a bunch
of unstable oscillators.
William Donzelli
aw288(a)osfn.org