Currency and Payment:
The baht (sign: ฿; code: THB) is the official currency of Thailand. It is subdivided into 100 satang. The average exchange rate is 1 Euro = 35,81 ฿ = 1,13 USD.
Any currency can be brought to a Thailand money exchange counter and converted to baht. Furthermore, visitors have a variety of options for using money in Thailand, from travelers checks to credit cards, though bargaining for goods is best done with Thai baht.
Banks or legal money-changers offer the best rates to exchange Thai baht or foreign currency. ATMs that accept Visa and other credit cards are easily found in the large cities and dispense Thai baht, while many exchange booths will give you a cash advance in Thai baht on your credit card with a good exchange rate, though they will levy an extra fee.
Major credit cards are accepted in most establishments and shopping centers, particularly the larger ones in Bangkok and the more touristy areas. However, there are occasionally additional fees placed on charges by both the retailer and your card provider.
In fact, you may be better off reserving the credit card for emergencies and paying cash for most purchases. While it's against the law for the Thai vendor to pass the fee that the credit card company charges them on to the customer(approximately 2.25% to 3.5%, depending upon card type), it's quite common for them to do so, and it's usually not negotiable -- you either pay the surcharge or don't use your credit card. They may even attempt to charge 4 or 5% instead of the 2.25% to 3.5%.
Transportation options :
Public transportation in Bangkok: tourists can travel around by bus, by train, by skytrain, by subway, by van, and by Song Taew (small pick-up truck with two rows of bench).
Taxi: Bangkok has metered taxis.
Tuk Tuk: a three-wheeled motorcycle, symbolic of Thailand, can be found around Bangkok.
Traveling by car, motorcycle and bicycle is quite convenient for tourists because there are traffic signs available both in the Thai and English languages.
Motorcycle Taxi: motorcycle taxis can be found close to street intersections or small allies for quick transportation and short distances.
WARNING - Electronic cigarettes are illegal in Thailand
While electronic cigarettes or e-cigarettes are used around the world as a way of helping people quit smoking, travellers coming to Thailand should be aware that these devices are in fact illegal in the kingdom.
Anyone found breaking this law by using an electronic cigarette – or vaping – in Thailand could be arrested and face jail time, or a fine several times the value of the illegal item(s). This applies both to foreigners and Thais.
Source : www.tourismthailand.org