Just got back from Turkey and used my visa card for purchase of gasoline. I was surprised when Visa (bank of America) added a 3% charge on my bill for the amounts charged. Do all visa cards have this charge

Most credit cards have a currency conversion charge.

I just came from FlyerTalk Miles board, Visa forum, where mre2b9 posted the following:

selection from CBS Marketwatch:

Credit cards defend currency fees
Plastic still offers best foreign-exchange conversion rates
By Andrea Coombes, CBS MarketWatch.com
Last Update: 11:00 AM ET June 3, 2002

SAN FRANCISCO (CBS.MW) -- MasterCard and Visa trade billions of dollars worth of foreign currencies each year by
virtue of acting as middlemen in cross-border transactions.

For the added work of paying merchants in their local currency, the two charge conversion fees that are being
challenged this month in a California court.

The complaint: The 1 percent fee isn't listed on monthly bills, but lies buried in the small print of the cardholder
agreements no one reads.
...
When making credit-card purchases abroad, travelers face the 1 percent charge and often an additional bank fee.
...
The lawsuit filed in Alameda County Superior Court in February 2000 challenges the hidden nature of the fee. ...

Even though credit-card exchanges are cheaper, travelers heading overseas can save money by choosing their
cards wisely.

MBNA, for instance, passes on the 1 percent fee without adding a fee of its own, while CitiBank and Wells Fargo
tack on an additional 2 percent. Providian Financial charges Visa Platinum holders an added 2 percent, also, but
regular Providian Visa and MasterCard customers don't face the added charge. BankOne charges Visa holders 2
percent and MasterCard holders 1 percent. American Express charges 2 percent.