Originally Posted by chacker
For your specific reference to mobile phones, may I recommend Mamboonkrong (MBK Center) in Bangkok...
They basically have one whole floor dedicated to cell phones - and there are deals to be found, as long as you're prepared to spend some time going shop to shop. If you don't mind a 2nd hand phone, the prices can't be beat. And, even if you're looking for a brand new one, I think the prices here are very competitive compared to anywhere else in Asia.
I forgot to mention a couple of things:
If you want the best price at MBK, have CASH in hand, as they'll charge you more if you're using a credit card, and don't be afraid to bargain a bit - they typically won't come down much on new phones, but they will consider it - especially if you're buying more than 1 item.
Best of luck! Let us know how it goes!