Smart Phones, Bluetooth and OSX

I'm thinking of switching my wireless carrier, and I am looking at possibly
getting a smart phone.
Since I have Bluetooth on my G4 Powerbook, I'd like to make sure that I can
sync up calendar and address information to my new PCS.

At a glance, it appears to me that Palm Treo is the most OSX friendly of the
phones. But that's my uneducated guess.

What do others on this group feel? What are you using, and any possible
advantages to one over the other. (Besides the obvious legal issue with
Blackberry - don't want my device getting turned off right after I buy it.)

Thanks




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