There are many Mambo and Joomla groups in Thailand. Most government and university websites are developed by Mambo. Also in the bookstore, you can find Mambo. I thought I was the only person in Thailand use drupal. This is not true now.
Check here my drupal sites in Thailand:
http://ibc.ac.th
http://atbu.org

Sorry, I am from China but work in Thailand. Currently, I am learning Thai but cannot read Thai. I consider myself a Thai, because I like Thai food so much.