US dollars and travellers cheques are your best bet. There are four ways to exchange currency: at a bank; through authorised exchange bureaus; at hotel reception desks; and on the black market. The best rates are offered by the banks, but the exchange bureaus are generally more conveniently located and have longer opening hours. The black market rate is worse than the legal exchange rate, so if you're offered better rates than a bank it's bound to be some sort of scam. Visa, MasterCard, American Express and JCB credit cards are accepted in the major cities and towns popular with tourists.
It's virtually impossible to exchange travellers cheques outside the major cities and tourist areas. Visitors heading off the beaten track will either need to stock up on dong, or conduct a private cash transaction on the black market. It's a good idea to bring a small calculator with you for currency conversions, unless you're the kind of person who can divide or multiply by large numbers in your head.
Government-run hotels and tourist restaurants usually add a 5% service charge to bills so there's no need to tip (although staff may not get any of it). Leaving a small tip in other restaurants will be greatly appreciated by the staff. You should consider tipping hired drivers and guides, and it's polite to leave a small donation at the end of a visit to a pagoda. Bargaining is commonplace but should be engaged in with a smile and considered a form of social discourse rather than a matter of life and death.
Copyright 2010 Lonely Planet Publications , all rights reserved, used with permission