Martin pointed out that the 'Mark' system isn't quite ready. I believe
he's right about that, but getting started has been made much easier.

On 1/1/05, The US and Canada officially (and quietly) required all UPC
scanners to accept the 13 digit code being used in most of the rest of
the world (at the time, our scanners only used the 12 digit code). This
means there is a universal, worldwide pricing system already in place.
The true Mark will be rationalized for conveinience and to combat ID
theft, but, while that ultimate solution is being phased in, it would be
simple to use the existing credit/debit card systems now in place. If
they were restricted to official AC cards only, I would think the system
could be functioning as quickly as cards could be distributed. Either
you've got an AC card or you go hungry!

Brad Richard