I needed a phone for my business (in-home computer repair) and the 3650 had just come out and looked like a good choice. That was in August of 2003. Since then, T-Mobile has replaced the phone and battery once and I still have the same problems - the phone constantly crashes. I get errors like &quot;Appserv main closed&quot; which causes me to miss calls and lose text messages.And if you use a car charger (I've bought 2 of them), the battery will not vibrate until you have charged it for a while using the regular wall charger. I've missed a lot of calls this way - if you listen to music while driving, you're not going to know someone is calling you w/o vibrate.Ultimately, I regret choosing this phone. If someone calls and I'm not there to pick up the phone I know that person will try one of my competitors rather than sit around and wait for me to call back. The only plus side is a nice carrying case that I picked up. And T-Mobile has been pretty awesome about the entire thing.Good - T-Mobile rocks, phone looks cool, nice carrying case that hooks on your pocket, features.Bad - P.O.S. phone that has resulted in lost customers and thousands of dollars.