Here's a directory style website and search engine focused on muay thai. They collect, index and show only quality muay thai websites, the search is powered by Google and restricted only to those websites, so you won't get all that blog spam or spam links.

This is the address: http://muaythaibot.com/

The sections are:

Muay Thai associations
Muay Thai camps
Muay Thai fighters
Muay Thai gear
Muay Thai movies
Muay Thai online games
Muay Thai reference
Muay Thai schools
Muay Thai techniques
Muay Thai training
Muay Thai video clips
Muay Thai women