Whitfield Diffie, Martin Hellman, and Ralph Merkle developed public key cryptology, the basis of all Internet encryption.

FORBES: You've Never Heard of Them, but They've Changed Your Life

Here, when not taking online courses on subjects like cryptology, identity manipulation and bomb defusing, students pay to be threatened with Taser guns, thrown into mud pits and subjected to deafening rounds of live ammo fired over their heads.

FORBES: My Son, The Bodyguard

Eric Hughes, a cryptology expert with Simple Access, an electronic-commerce consulting firm, conducted his own experiment: at a technical conference, he issued a roll of pennies to every participant and explained that there was a one-cent charge, payable into a box beside the door, each time anyone entered the main room.

ECONOMIST: So many ways to pay online