Any way to lock Autofocus when camera is not in use to help with Camera rattling?

After testing my new iPhone 4s and trying to debug the rattling near the camera (which I guess is a known issue with the 3GS, 4, and 4s) I found that when the camera is locked on Autofocus there is no more rattling. Not sure why this is or what specifically the camera lens do when they are not being used, but it seems that if there was a way to have the camera go into autofocus when not being used, this would solve all of those annoying rattling issues that are posted all over the internet and ASC.

I know some people have had their iPhones replaced and some have been lucky and received a new one that has no rattling or very little, but trust me, it won't be long and that annoying rattling will make its way back to your phone. I contacted Apple customer service and they were not aware of the issue....which I find hard to believe, but suggested that I go to the Apple store and see if they can solve the problem. They were very helpful and would set an appointment for me, but it was interesting that they had not heard of this before. It is all over the forum. The issue with getting a replacement phone is yes I may have a new one that doesn't rattle as much, however, I could get one with a bigger issue, its a chance that some may choose to take.

For those not aware of this issue, if you tap the rear of the phone up near the camera, there is a small rattling sound that comes from most units. Feel free to google iphone rattling and see what you get...its interesting. You can also hear it if you put the phone down on a hard surface...its sounds like something is loose inside the top of the phone. Some have suggested loose buttons, some of said that its the vibration unit in the phone, but the only thing I could do to get it to stop is to lock the autofocus. I have gone to a few stores that have the iPhone 4 and 4s and all the units had this rattling so it may just be something that you have to live with...Great phone, I guess nothing is perfect.