A graceful welcome
Thailand's traditional form of greeting is the wai, a lovely prayer-like gesture accompanied with a little head nodding. Social status is indicated by the height of your wai and depth of your bow: inferiors initiate the wai, while superiors return the wai with just a smile, under no circumstances should you wai waitresses, children, or clerks-this only makes you look ridiculous! Save your respect for royalty, monks, and immigration officials.
The 'wai' can be used to great effect on foreigners. Imagine if you will that you have just arrived from a delayed 12 hour flight, you are hot, tired, and somewhat short tempered. You arrive at your hotel to be greeted by the beautiful 'wai', this graceful unexpected gesture can easily dispel your short temper, making you content ( sabai jai )