You can use the Treo without the email/data. I find that VERY useful, but it's not for everyone. The advantage of a Treo is the ability to have ALL of your cotacts - their associated phone numbers all within your phone. Update all your information in Palm Desktop - calendar, contacts, etc and it all updates on your Treo -- and back. I can't live without my Treo. It's just light years past a regular cellphone. If you've used a Palm device, then this will converge your Palm and your cellphone.
Additionally, there are thousands of
software titles available for the Treo since it's Palm OS based.
We have good deals now on the Treo 600 in our store -- since the Treo 650 is the new model. If you don't see the 600, just select 650 then click in the left nav to see "other phones".
Let me know if you have any other questions. Good luck with your decision.