The Rosetta Stone software uses images and interactivity to teach you in a natural way. By using pictures and words you learn the association much faster than just repeating what you hear. This reinforces the learning and really helps you to remember words much easier. I bought a copy of Rosetta Stone Thai while I was in Thailand last May and while I like it a lot and it has increased my vocabulary it never really works to teach me what I want to know specifically but teaches me the words and phrases it wants me to know. Very helpful and a great tool for the beginner.
Pimsleur Thai is another program using recorded Thai by native speakers to reinforce learning by repetition but they do it a little better than most by giving you complete sentences to memorize but then they use the sentence in conversations switching up the male and female attributes and structure which helps you to retain what youve heard and been repeating along with the recording. Pimsleur lessons can be bought online through various outlets. The first 10 lessons can be found for free on the web by searching Pimsleur Thai.
Learning Thai.com is one of the best resources out there and best of all its free. They cover the gambit of Thai language from learning to speak Thai to learning how to read and write Thai. Recordings of words and phrases by native speakers to help you with pronunciation and tone as well as an English/Thai -Thai/English online dictionary. Absolutely the best online resource for the Thai language.
Whether you are going to Thailand for a two week vacation or have more in mind, learning some of the language before you go can be fun and a rewarding experience when you use what youve learned while enjoying your trip in Thailand.