The official currency is the Kyat (MMK) but US dollars are accepted everywhere. Current notes are: ks 1000, 5000, 500, 200, 100, 50, 20, 10 and 5 bank notes.
At the time of writing the exchange rate is US$ 1 = 988 Kyat and 1 EURO = 1327 Kyat (December 2013, please note that this can change significantly on a daily basis).
It is now possible to find money changer from official private banks in every airport and in city centre. They usually offer better rates than the black market and they accept US Dollars as well as Euros (maximum amount: 2000USD).

Please note that some hotels may need an imprint of your credit card as a deposit during your stay, which is a normal procedure. However, this deposit can be made in cash and will be refunded upon check-out