Summary: I've had my Palm Treo 680 since 2004. The battery cover wouldn't stay on and would fall off constantly. The face plate had 2 cracks. Decided it was time for a new phone. I have never had a use for any of the internet features and never had to pay AT&T for those services. AT&T DEMANDS that you pay a fee of $30.00 per month extra to your service every month for features I don't need on any new phone.
Summary: I bought the used unlocked Treo 600 Phone two weeks ago and was immediately impressed with the number of features available on this PDA inexpensive phone. It has a 1M-pixel camera, video camera, and speakerphone. The Treo 600's size is perfect for carrying in a pocket and the battery has a pretty good lifespan of roughly 16 hours.
Summary: If you are looking for a great internet phone--this isn't for you. Buy a Droid. Buy an iPhone. Once past that, though, this still works great and does some things, like keeping your calendar sync'd on your desktop, better. It is a good ebook reader and a good mp3 player. It is a great PDA. There are still lots of available apps. Maybe it doesn't look as cool and it is certainly true that it is a lousy phone if you are into web browsing or streaming video or the like.
Summary: Although this model has been discontinued, the Palm Treo 600 was just what I needed to replace my Palm Treo (70 I think?). All I needed was a basic PDA - cell phone with a keyboard to perform text messaging. The 600 has the availability for web access (which I don't use since this phone does not have a contract, which I could purchase, however, I only spend $50.00 every 3 or 4 months to purchase minutes).