Potential Problem?

Hi guys,

I just upgraded to an iPhone 5 (16GB black) a few days ago, and I noticed a strange sound when I tap the phone with my finger. (For example, tapping to open an App).

It sounds like there is something loose inside the phone. I tried tapping my finger around the outer edge of the phone and I can hear it quite easily. Tapping in the middle of the phone doesn't really make the noise, but the farther out from the center of the phone I tap, the more apparent the sound becomes.

I do not have the phone in any case; it is naked, so I'm pretty sure that the sound is coming from within the phone.

Has anyone had a similar experience? I've only had the phone for a few days so I can still take it in for a return/exchange (bought at Best Buy), but I figured I'd see if anyone else has had a similar experience before I make the drive.

Thanks for the help.