Too often, when I use a credit card outside the US, the establishment wants to run the charge in USD, instead of the local currency. That sounds good at first, but the exchange rate is horrible. You pay 5-10% on the exchange, rather than the 1-3% your credit card might charge.

I have no problem when this is done after asking. But I'm finding it done more often without asking, or in some cases, even after I specifically told them not to do it ("oops!").

I'm gathering up my receipts, and disputing every one of the overcharges in the latter category (where I agreed to a price in the local currency, not the inflated price in USD, or when I specifically told them to charge in the local currency) for which I have a receipt.

I urge you to do the same: if you've been overcharged (check your receipt, see if you were charged in USD) without your approval, dispute the overcharge with your credit card. Calculate how much the charge should have been at the real exchange rate, and dispute the difference. You can easily use Google to convert currencies: for example, type "50 gbp to usd" in the Google search box.

My hope is that if enough people do this, the merchant banks that encourage the forced USD conversion will be drowning in too much paperwork to make it worthwhile. Refunding a few dollars is no big deal for them, but being carpet-bombed with disputes can hurt.

As for the Quixotic angle, I figure I will spend half an hour on this, and make $20 in after-tax profit. That's not a good rate of pay, but psychological victory counts for something -- and maybe if others join me, we can help stop this practice.