I had the pleasure of attending a lecture given by Michael Badnarik on U.S. Constitutional history and law. He was visionary enough to accept silver as tuition payment. Below he blogs about the hazards of embarking upon silver coinage.
http://www.constitutionpreservation.org/articles/march-5-2011/liberty-dollar-trial-begins

On a whim, I brought a few silver dimes with me in case there was an opportunity to buy something. Turns out that Michael B himself was not selling anything, but there was a local freedom-loving entrepreneur who had set up a table in back and stocked it with books and CDs. All those items were “free for a contribution” which is a nice way of making money without “selling.” At one point he said that the CDs cost him 40 cents each to burn and print color labels, so I whipped out 4 old silver dimes and handed them over. Viola! He got $10 worth of silver (at then current price of ____), and I felt like an insider (esp. since those silver dimes cost me less than $4).

Surprisingly, I was the only one who paid for my tuition in full with silver. One other gentleman paid for half his tuition in silver. I used some Mexican Onzas I’d bought back in the 20th century for less than $10 each. Everybody wins. http://www.kitco.com/charts/historicalsilver.html