[Bossman]

You've got some excellent advice from the folks here already. I like the idea of geting an unlocked triband on ebay before you go though. You can get a very good triband phone for around $100 or less on ebay. The Motorolla L6 is not a bad one. May be for a little more than $100 brand new and unlocked. You would also have the phone as backup here or for future trips.

You obviously need in international sim like riiing. But, you do not have much time. Check the buy/sell/trade forum. Someone in the US had a riiing sim for sale recently.