Ask that same question on an Apple Forum... I think you know what the answer would be... the Curve is an excellent choice now... Javelin might be the answer in 6 months, but the Curve is a great choice.
The iphone 3G has connection issues with the 3G network. I have seen multiple issues with it staying connected to AT&T's 3g with drop calls, drop data. I was thinking of the iphone 3g but one thing the iphone doesn't have is a hardware replacement plan/equipment insurance. That's what turned me off from it. What would happen if you drop it or it gets stolen, or it breaks? You would have to purchase a new one.