Re. phone calls from Thailand. You can get a sim card in many places......heaps of places selling them in MBK and Pantip Plaza but also 7-11. One thing you need to know about these is that they are valid for a particular period of time only so you need to be there to add baht or pay a whole lot before you leave. With one card that I had, I stood in 7-11 buying 200 baht top up cards one after the other until I'd put 800 baht on the phone. It ran out before I got back to Bangkok - grrrrrrrrrrrr . very inconvenient because next time I went, I had to get a new simcard/new phone number and all my BKK numbers (dentist, hairdresser, hotel, limo service etc) were lost. Awhile ago DTAC had a special offer - original simcard lasted 12 months and could be topped up during that time or afterwards. I've still got it. Look in DTAC shops to see if they still have these special deal cards.