This essay considers some prescriptions that are currently popular regarding exchange rate regimes: a general movement toward floating, a general movement toward fixing, or a general movement toward either extreme and away from the middle. The whole spectrum from fixed to floating is covered (including basket pegs, crawling pegs, and bands), with special attention to currency boards and dollarization. One overall theme is that the appropriate exchange rate regime varies depending on the specific circumstances of the country in question (which includes the classic optimum currency area criteria, as well as some newer criteria related to credibility) and depending on the circumstances of the time period in question (which includes the problem of successful exit strategies). Latin American interest rates are seen to be more sensitive to US interest rates when the country has a loose dollar peg than when it has a tight peg. It is also argued that such relevant country characteristics as income correlations and openness can vary over time, and that the optimum currency area criterion is accordingly endogenous.