Are there any restrictions on the travel checks (Thomas Cook, American Express, Visa etc.) or credit cards in Russia?
No, there are no restrictions. Credit cards and travel checks are not to be declared and can be used freely. Russian banks can cash your travel checks. You can also buy travel checks in Russian banks. You can find ATM Machines in the hotels, airports and banks. VISA. MC. AMEX. DC, Eurocard) are most widely accepted in major cities (such as Moscow and St. Petersburg). There are even many places to get cash advances on credit cards these days. Still, travelers checks are a good security against theft. It is therefore a good idea to take along some larger denomination checks which you can cash if your money runs out. In this event, the better known checks like Amex. Citicorp and Visa are most recommended.