My favorite one, and the one which may be most apprehendable to the public, is an ATM-card gate in which the purchaser swipes his card into a secure mosaic screen using a card reader at home (they're pretty cheap these days, and could get cheaper if this became prevalent). As a rule of thumb, the purchase of any hardware of any kind, no matter how inexpensive, drops your potential market by a factor of ten. That means anything put up on your spiffy Sparc machine and it's attendant code should be able to: 1. Generate to purchasers and take in digital cash from sellers. 2. Identify double spenders. Why item two? Have you made a decision that charging for deposit attempts doesn't work, or that identity is still needed for some reason? Eric