I love the Palm Treo 680!!! I have T-Mobile and Until just recently had the sidkick3. This phone in the best I've ever had. I wonder why T-Mobile doesn't have it on there plan. We'll any way I have my E-Mail synced up, The camera is really really good for a phone. Way better than the Sidekick could ever be. The Treo also takes Kick ass movies. The built in Mp3 Player is awesome, and I love that it take s a regular Sd card not an Mini sd. So much easier to transfer files. Clarity on calls is very good. This is a well designed phone. The only thing i wish Palm in cluded in the built in software was the graffiti writing option. They give you the stylus and everything what the hell!!! You can download after market software to make it happen for like $24.95. That's my only gripe though. Just make sure that if your using any other plan other than Cingular that you get a phone that is totally unlocked or you can't use it.
I decided to replace my Treo 600 which had a terrible buzzing sound during calls. This phone would work with all my third party applications and had improved resolution, internal memory etc.,
My only dislike is that sometimes the OS slows up depending on the activity, for example, If I am browsing the web and a text message comes in or if I am on a handsfree call while in my calendar, the navigation slows down. I even had a few restarts.
Otherwise, the phone is great and the service has been great.