Watch for hidden ATM, credit-card, and exchange fees.

Cards:

Many banks and credit-card issuers are now gouging their customers with "conversion fees" and other surcharges on foreign transactions.

Also, prepaid "traveler's cheque cards" can make you feel like the victim of a Parisian pickpocket when you see how little money is left over after you've paid the fees.

Cash:

Currency-exchange commissions and fees can be mind-boggling, so get your cash from ATMs when you can. (A while back, we saw that a Travelex office in Venice was charging an 8.5% commission to change U.S. dollars or pounds sterling into euros, plus a €3,50 handling fee.)

Also, take claims of "no commission" with a grain of salt: The exchange counter may not be itemizing its percentage, but you can be sure that a hefty profit margin is built into the quoted exchange rate.