Dynamic Currency Perversion is a disgrace and a sly way to rip off travelers. I have heard it discussed but never came across it while abroad until now. In a recent trip to Tenerife, Spain (otherwise great destination) I found that a couple of the gift shops offered-- I mean forced this on me. It actually said on the receipt that I certify that I was offered a choice of currencies and choose to have my Euro purchase converted to US dollars. I told the shopkeepers that this is not true, that I want to pay in Euros, and that I refused the dynamic conversion. They didn't understand why I was angry and had no way to overriide it-- said it was a function of the banks not them, showed me a pile of receipts from other tourists who paid in other currencies. So I crossed off the dollar amounts and the "I agree to pay in USD" on the receipt but of course I found when I got home that the charges had gone through anyway at the inflated conversion rates, with the additional VISA surcharge on top of it. This is patently unfair and sleazy and should be illegal but I got tired fighting about it and didn't spend enough money on gifts to dispute it with my credit card company-- though I feel I should do so just on principle. Not one of the restaurants tried this, just gift shops catering to tourists.