Isn't it funny, then, that people around the world who are under no legal obligation to follow U.S. legal tender laws come up with pretty much the same valuation of the dollar that we do domestically?

My argument is very simple. A government creates the "thing" called money, backed by the full faith and credit of that government. Peoples' perception of the stability and credit-worthiness of that government factor into everyone's valuation of that money, but the value at the time it's created is easily observed. Of course that value can change, but so too can the value of gold after it's mined, so I don't see any practical difference in how "intrinsic" this value is to the paper money vs. gold. Legal tender laws do ensure that the fiat money is privileged above other media of exchange, but if it were truly just those laws that were propping up the value of the dollar, then nobody outside the U.S. would want to accept dollars to settle debts.

On inflation targeting, as I said upthread, it's not like our central bank's preference for a small but nonzero amount of inflation is a secret. Just as we expect drivers to be able to follow the rules of the road, savers need to factor inflation expectations into their savings plans.

Why do central banks tend to aim for low but positive inflation? Because the mainstream economic consensus is that deflation is the worse of two evils. You don't want too much of either, because both can spiral out of control, but if you have to have a little of one (since you can never aim for stasis with 100% accuracy) most countries have decided they'd rather have a little inflation. Yes, you slowly erode some savings, but you retain the ability to lower interest rates (which obviously can't go below zero) and you don't lose employment the way you do with deflation when everyone begins hoarding money instead of spending it on capital and wages.

But the real question, again, is: why are we talking so much about inflation when it barely makes the list of threats to the US economy right now? Even if actual inflation were higher than what CPI shows, the alternative to inflation today is mass unemployment and crippling austerity. How's that working out in Europe? You can't even blame it on the Euro, because the UK has been tightening its belt with adverse effects, and they have their own currency. Where are the austerity / tight money success stories?

Obviously when the economy is healthy again we take our foot off the accelerator and raise interest rates to soak up excess liquidity, but anyone who wants to moralize about theft from savings accounts needs an answer for what we would do about the mass layoffs and misery that would come with a tightening of monetary policy. They also might try to find better evidence of current high inflation than citing record highs in non-inflation-adjusted stock market indexes and a site that says that a Big Mac meal cost a dollar in 1990.