Learn some elementary Thai before you go. There are several courses on CD available. Many people there speak and understand English, but a few words in Thai (even with rather mediocre pronunciation) will be useful at the markets, and you will be praised as the greatest linguist of all times ...
It's fun, too. I learned a few rudimentary phrases from a Lonely Planet guide before going to Phuket and it's such a wonderful way to engage with the locals.
Phom chawp Thailand!
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)