Treo 680. Which one is best? I want to upgrade to a PDA phone and I was thinking on getting a Blackberry Curve or the Palm Treo 680. I am currently with ATT and I don't want to change servers. I can't not afford a iphone (in case somebody suggests it). So please, if anyone knows the main difference between the two and which one will be better for the buck, I would appreciate the feedback.