e$: A prima facie business model for a digital cash underwriter.

[hughes@ah.com (Eric Hughes)]

   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