Yeah, so I'm about to be on my third iPhone 3G (I know, I know... many others have gone through quite a few) Regardless, the first one I got worked fine up until a couple of weeks ago when I upgraded to 2.1. Then it decides to give me this error "The iPhone _ cannot be used with iTunes because the information required for activation could not be obtained from the iPhone." Take it in, get it replaced for a new one. Now, after upgrading to 2.1 on the new one that has been working fine, I'm getting the same error. This sucks.