I travel to Thailand 3 or 4 times per year and having a cell phone with a local number saves me a lot of money. Local calls are dirt cheap and long distance calls back to America are inexpensive.
All you need is an unlocked GSM tri-band or quad-band phone a Thai SIM card. A SIM, or subscriber identity module, is that little wafer chip about the size of your thumbnail under your battery in your cell.
You can get SIMs in almost every country you travel to and it only takes a couple of seconds to swap them out.
The problem with American cell phone carriers is that they lock the SIM to a specific carrier. So, you have to get it unlocked, a relatively simple task that will only cost a couple of dollars. You can try to get your service provider to unlock your SIM, but most likely you will have to be a long time customer with a compelling story to get it unlocked.
The easiest way to overcome this is to buy a cell phone in Asia. They are inexpensive and are not locked to specific carrier. New and second-hand phone are readily available and the prices are very reasonable.
The only real problem I have had is maintaining the same phone number in...