I'm in the market for a cellphone - haven't decided which one yet but am looking at the Sony Ericsson P910i or similar (phone with pda-like capabilities but not too big); I'm quite flexible.

I will be in Tokyo, Bangkok, and then Singapore in the next few weeks. Anyone know where would be the best place?

Also, I have a friend going to Seoul at the same time who could pick one up for me - would that be cheaper?