Anybody know if a visa is required for entry to Cambodia for Thai Passport holder for a stay of 15 days?

Vietnam does not require - but can't find a definitive yes or no from various travel and embassy sites.

Thanks!

Yes, Thais need to get a visa for travelling to Cambodia.

You can get a visa at the border (1000 Bht)

A single-entry tourist visa ($20 plus one passport photograph required) is valid for thirty days, including the day of issue, and can be extended once only, for one month. A business visa ($25 plus one passport photo) is also valid for thirty days, and can, in theory, be extended indefinitely and converted into a multiple-entry visa.

http://www.tourismcambodia.com/Highlights/be4ugo/visa.asp

Thanks BambinA for quick pointer to Cambodian web site.

The URL gives all the info.

The visa is for my daughter, (Thai/British) who plans an escorted overland from Vietnam to Thailand in April.