I just bought a Motorola V400 GSM quad band phone that I am using with Cingular Wireless in the USA. Technologically, the Motorola V400 works on GSM/GPRS networks on the 850/900/1800/1900 frequencies.

I want to bring it to Thailand when I am on vacation, but I have been told that it is best to buy a sim card for use with a local provider in Thailand rather than "roam" with my own account. I have also been told that I will need to have the phone "unlocked" for the new sim card to work. Does anyone know of a place in Phuket that is reliable that could do this for me?

Also, I plan to use the phone in Phuket, Phi Phi Island, Ao Nang and Bangkok. Is there a wireless provider that would be better than the others for use in these areas?

Thanks in advance.

First of all, I'm not sure you need to unlock. Go to Big C department store at lowest floor it's full of mobile shops. Ask to try a SIM card. I brought my phone from Italy and it works perfectly, but of course can be different with US phones.

At Big C they can also unlock your mobile if needed.

There are three companies : AIS One-two-call, DTAC and Orange.

I have a DTAC and my wife has Orange and we do not have any problems in Phuket and Bangkok.