For calling Thailand to the U.S.A. I think the options fall into some general categories:

1.) low cost/low quality: ~ 1 baht/min via calling cards ot TrueMove H 00600

http://www.thaitelephone.com/EN/call...enet/index.php

CAT phonenet cards offer free local access and/or call-back, rates are 1 baht to mobiles or land-lines in the U.S.

http://truemoveh.truecorp.co.th/3g/s...aid/entry/2271

2.) Each mobile service provider offers low rates, maybe a bit better quality:

TrueMove H 006
DTAC 004
AIS 005

~ 3 baht/min.

3.) Standard rates: 001/+1 are 6 ~ 8 baht/min

4.) CAT(009) TOT (007) ~ 3 baht/min


Calling from the U.S. to Thailand there are a lot of calling card options, either sourced in Thailand or the U.S. Quality/completion rate will probably be spotty. A fuller service option like AT&T might offer better quality, albeit at a higher rate.

http://www.thaidial.net/

http://www.thaitelephone.com/EN/call...land/index.php


For me, I use my magicJack (at home), GoogleVoice (GrooVeIP) and 004 (DTAC) to call the U.S. When in the U.S. I use a pre-paid AT&T calling card to call Thailand. I've used idPhonecard also, the quality is OK, but call completion is ~ 50%. http://www.idphonecard.com/idreg/rat...&countryto=THA