Did you not read my post? The 3GS has the same RATTLE. It's the CAMERA. The one on the BACK, not the front.
Dear god does anyone pay attention anymore?
You’ve been around long enough to know many posters just read the title and zing out a post.
I'm tempted to take a youtube vid of this. It's loud. I do it on my 3GS and it doesn't sound like this.
It’s possible yours is looser than normal. Just get a replacement.