Google has added Thai language to their translator...

[Takiap]

Yes, I think they added it quite some time ago, because I seem to remember using it a while back, but as others have mentioned, it's not perfect, at least not yet.

[BaaBaa.]

can't seem to find the Thai letters for translation, even though connected to the web to use Google translate.....

Use http://www.google.co.th/ and there's a pop up keyboard.

[Korkenzieher]

I have an HTC Touch 2 and got Thai keypad added at Market Village too. JMart if I remember correctly. Free when I bought the phone. It also has PinYin Chinese - not that that is particularly helpful in Hua Hin.

As for pop-up keyboards, the PoomsanBecker PC dictionary has quite a good one.