Hello everybody, just want to say first that I love this forum and it's the first place I come to search for any information that I need regarding my iPhone's. With that said, I can't really find the answer to this specific issue. So I bought my iPhone 4 in June of this year and absolutely loved it (long time Blackberry user), but about a month ago the noise cancelling mic went out on it. I had a line on my account that was available to upgrade, so I went ahead and upgraded to the 4S and love it as well. After I got my 4S set up and running, I scheduled to meet with the geniuses at the Apple store and they swapped my 4 no questions asked for what I'm assuming to be a refurbished unit. I don't have any issues with that, but my question is whether or not the factory 1 yr. warranty (that should be in place until June 2012) will be available to the person that I sell the 4 to. I only wonder because the serial number of the phone itself is obviously different from the original equipment that I bought. Thank you to everyone in advance for help.