I did a lil research on this topic and found mostly broken links or services that load you with spyware.

what program/service do you use to send your Thai GFs sms text mesages from your computer? Are there any free services that work well sending to thai mobiles??

HI i use IPIPI.COM it not free but it works well im in saudi desert only internet conection no mobile coverage it costs 12 dollar for 100 txt i use to keep in touch with my tgf and she txt s me back to my computer the more txt you buy the cheaper it is

I have used VoipBuster. It is not free but reliable and messages are delivered very quickly.

I have been using Voipdiscount.com for about 12 months now. You have to put in an initial payment from your card. I put in 10 Euro and that money just "sits-there" until you have had all your free calls ( 60 days if I remember right) and after that some calls are free and some aint. I was ringing my T.G. for up to about an hour a day for free. You can also send text messages for free but I never bothered with them because of the free calls. Also you can use it from anywhere in the world provided you have your computor with you of course. Have a look at it on the net. Unless you already have ?.

The best and cheapest... is for your recipient to have a HAPPY or DTAC SIM. Then you just need to register the SIM card to receive 50 free web to mobile telephone messages to any telephone on the DTAC network.

You can do this with yahoo messenger and its free. I send sms messages from my PC in the UK to a friend of mine in the phillipines. If she replies it costs her but its cheap.