I just got a T Mobile phone that will do FP for $2.99 a min. as well as let me use AOL Instant Messenger for a very small charge.
It is not unlocked now, but, the only place I will ever need to pay that amount per min is FP. For the other travel I will be doing, the rate will be $.99 a min. I think it's cheaper than renting plus the minute cost is higher. Cingular and ATT will not give you international use until you have been with them at least 90 days.