http://www.appleinsider.com/articles/10/06/07/apple_unveils_redesigned_thinner_iphone_4_with_two_cameras.htmland run the video. After about 5 minutes you will hear Jony Ive, Senior Vice President, Design, state that the iphone incorporates 'an entriely new grade of stainless steel' If any one knows more then please let us know!