Palm vs Blackberry?

I am having a hard time deciding between the two. I currently have Alltel, which will be switching over to Verizon pretty quick here. I would like to get a smartphone before the switch, so I can have the Alltel prices grandfathered in for the next two years, which will save me $25 a month over Verizon's prices for the similar plan.

I just cannot decide which would be better. I have the choice of the Blackberry Curve, or the Palm Treo Pro. Can anyone tell me their pros and cons with these phones?

Thank you!