Don't know if you have heard of them but Splendia
specialise in discounted luxury and boutique hotels. Worth checking if you're going to stay in Thailand... anyway, I heard today they are running a promotion which gives you an extra 10% off - all you do is enter the promotional code TH2010 and it'll give you the extra discount.
Handy to know! By the way, if you book using the above link, the forum gets a little commission as well - so everyone wins!