Why would you get another visa from the Thai embassy in Cambodia? You still have 2 entries in Thailand left after your first stay and extension on the visa you just received.

ok I think I got it all wrong. so I go to thailand, stay for 60 days & get an exemption for 30 days. then I go to cambodia, and when I come back what happens at the border? do I get another 60 days or 15 days or what?
also the guy at the consulate said there is a limit of 90 days in 6 months. but here at some posts I read that this is no longer applied. so which one is true, is the guy at the consulate misinformed?

@ 736. You've got a triple-entry tourist visa ( if you described accurately )
The validity date applies to the use of the first one. You get 60 days on the first one, extendable on day 59 / 60 by another 30 days for 1,900 baht if you so desire. (puzzled why you call this an exemption, it isn't - it's an extension).
Come back by land from Cambodia and you use the second 60-day visa. The 15-day period applies to persons from countries on the visa-exempt list who don't have a previously arranged visa, and who are given a visa-exempt stamp for a stay of 15 days by a land border post (this is 30 days if arrival is by air). Again, you can extend this by 30 days for 1,900 baht. (and this yet again by 7 days but very few bother with this as it's not cost-effective)
If you're still around and need more time in Thailand at the end of all this, you then use entry number 3 ("good for three visits") on the same basis. In all circumstances you do have to leave Thailand at the end of the visa period, even if you only turn right around and exit whatever country you exit to and then come right back into Thailand.
Whatever entry stamp you get in you passport, whether it's a stamp against a 60-day tourist visa or a visa-exempt entry stamp for 30 / 15 days, they always expire when you next leave Thailand.
In theory, the maximum time you COULD spend in Thailand on your triple entry is 3 x (60307) = 291 days, though you must exit and return each time at the end of the maximum 97 days per entry.
The "90 days in 6 months" only applied to people continually entering on visa-exempt stamps (which was basically aimed at 30-day tourists attempting to live longterm) and in any event it has been discontinued.
"ok I think I got it all wrong. so I go to thailand, stay for 60 days & get an exemption for 30 days. then I go to cambodia, and when I come back what happens at the border? do I get another 60 days or 15 days or what?"
You get an extension of 30 days, not exemption. At the border you'll get another 60 days, which can again be extended for 30 days.
"also the guy at the consulate said there is a limit of 90 days in 6 months. but here at some posts I read that this is no longer applied. so which one is true, is the guy at the consulate misinformed? "
The guy at the consulate is misinformed.

BangkokBoy & stevenl thanks a lot for your great answers. it is really great news that I get 60 days when I reenter, I wasn't aware of that.
and sorry I meant extension, not exemption. english is not my native, so there was a little confusion. :)
again thanks a lot both of you for taking your time...
Visa extensions are obtained at any Immigration checkpoint (in Thailand).
See http://www.immigration.go.th/nov2004/en/base.php#
(click on the "Checkpoints" link at top)
The 7-day extension on visa-exempt entries still costs 1900 baht. So if you're travelling through Laos might want to get a tourist visa at the Thai consulate in Vientiane. Upside is they're currently free of charge, downside is it takes 2 days.

Hi I am from NZ and so get a visa exemption. I am travelling to BK then into Laos then back into thailand by land for 21 days so I will be needing an extension on the 15days. How can you get the visa extension, can you get it in Thailand or do you have to apply before you go? We will be coming back into Thailand at Huay Xai/Chiang Kong.
Any advice/info would be greatly apprieciated!
Sarah

Hello I would like to ask a question of tourist visa of Thailand.I am a Japanese cyclist.
I will fly to Bangkok from Australia soon.i have already got flight ticket to there but donot have return ticket or any transportation ticket which is going out of Thailand.i will across the border to Cambodia by myself within 30 days.Probably i could get a visa on arrival at the airport but i am curious to know.

No Visa On Arrival is only for nationalities that don't qualify for visa free(exempt) entry (which is NOT a visa) . Australian check- in staff are very strict about the need for onward ticket . You will need to get visa if you don't have onward ticket . Once you are in Asia its not aproblem to fly one way from other cities in the region , but from Australia , Europe etc , there is big risk of being denied boarding if you don't have ticket or visa.

thank you very much for your advise.
people say that "look before you leep".
just in case i will go to the Thai embassy in Australia for applying tourist visa.
of cause making an appointment first.
but it sounds quite strange because you guess that staff of flight company would deny
boarding to Thailand.