[nhaehnle]

Yes, you are right that I was looking at gold vs. fiat money without considering gold-backed paper money. I was in a biased frame of mind because the GGP was saying that with gold, there is no corresponding liability. With paper money you have such a corresponding liability, whether gold-backed or not.

About the US tax system, which I don't know too well: what about exchange of foreign currencies? Are they subject to capital gains or some other form of tax? Does the capital gains tax actually apply if you use gold for payment, and not just if you sell the gold in exchange for US$?