More about it here.
Competing currencies in Utah and Missouri (and maybe a dozen to follow), with no barter involved, no need for stores to "accept" anything but a debit card. Fed Notes, no different than volatile bitcoins - used as an interim medium of exchange only, or transfer medium - NOT as a store of (de)value. THAT is the power of what Utah is accomplishing now, and what Missouri may do later this year. You can save in gold and silver coin, freely converting it between other forms of legal tender, and spend it like regular money, without the pain of Fed note devaluation.
Exciting stuff. Thier's Law may yet have a shot in the near future.