[Telepathic Intruder]

Those aren't as useless as you might think. For example,

these were used by the ancient Egyptians, around the time of the Pharaohs. But the red led numbers would get dim and burn out over time. And you only got about a half hour of use after every recharging. So they invented the abacus instead, which lasted longer.

[cynwoody]

For example,

these were used by the ancient Egyptians, around the time of the Pharaohs.

Actually, the ancient Egyptians were far more advanced than that. Did you know that the Great Pyramid of Giza was constructed by a fleet of giant robotic quadrotors? Unfortunately, due to a bug introduced when the engineers overeached, the marvelous machines all flew out into the Indian Ocean and deep-sixed themselves, and Pharoah ordered the engineers executed.

The technology is only now in the process of being rediscovered, as yet only on a limited, miniature scale ...

http://www.youtube.com/watch?v=W18Z3UnnS_0

[RightOnline]

...not to mention that RPN used to drive them crazy, leading to various wars fought purely out of frustration.

[skinkinthegrass]

ahhh..hp35! :)