I also wanted to thank Mark for his podcast on Gold. Very clear and concise.  One small side note that i didn't hear him mention, so forgive me if he did and i missed it, but the reason they put ridges or writing on the sides of coins was to prevent another form of devaluation or inflation. When only a smooth edge existed on Gold or Silver coins you could shave off a small bit of the precious metal. The coins over time got smaller and thus lost value. Once the person had accumulated enough of the shavings he could melt it down and use if for exchange. Thus the stated value of the coin and the actual value of the coin did not correlate.

Ironic that when the State converted our Silver coins to clad, copper and nickel, they left the ridges in place.