Money in Vietnam
The currency in Vietnam is the Dong (abbreviated “VND” or just “d”). There are quite several denominations, smallest one is 500 dong and biggest one is 500, 000 dong. Coin is not widely used. Credit card is increasingly widespread in big cities, but remains limited elsewhere. And though it is possible to pay in USD or EUR, it is easier to bargain in local currency.
Money in Cambodia
The national currency of Cambodia is the Riel (KHR).
While for many years, there were no ATMs, now you can easily find in big cities. They will distribute mainly Dollars USD. This is the most stable value for the change.
No problem to exchange traveler's checks in dollars in banks.
Money in Laos
The national currency of Laos is the Kip (LAK).
While for many years, there were no ATMs, now you can easily find in big cities.
No problem to exchange American Express travelers checks at banks in Vientiane or Luang Prabang.
In 2011, $ 1 is equivalent to about 8,000 kip, and for € 1, we obtain 11 000 kips.
Tipping
Although tipping is not a norm in Southeast Asia, it is highly appreciated. The decision of whether to tip or not depends entirely on your satisfaction.
Whom to tip: your guide and driver should come first in the list. Expected amount for a guide is 10 USD / group / day (and if you are very happy). For long trip (10-15 days), you may reduce the amount. The driver is usually tipped half that amount. Tipping is generally not popular in cafes and restaurants, except those run with a cause (eg. helping children with disabilities). Of course, you may tip if your taste tells you so. To conclude tipping is totally up to you, no one will judge you on that.