I can't start 'my own' currency, perhaps with a critical mass of people who think this is a better system that would be viable.  

And as for Gessell, you are now claiming that he was not a 'real economist'.    This is utterly untrue, he was an influence, among others on John Maynard Keynes.  This idea has merit and again you cannot present any argument against it.  'It would become worthless' Why?  There would still be 21 million coins, this system only increases the velocity of that money and discourages hoarding.  The value of the coin remains the same. The idea that hoarding is a good thing, that is the really crackpot thing I heard people claiming on here.