It's not a localized problem, anymore. It looks like there is a serious manufacturing fault in the new iPhone 3G, specifically, the cases are cracking. The problem seems to be happening primarily in the white phones, but it could effect all of the new 3Gs.

It appears that the metal frame on which the plastic case attaches is too small. This stresses the plastic to the point of cracking. Many are reporting that their brand new phones are cracked or have small fissures on first sight. The cracks are appearing mainly around the headphone jack and buttons. 

All phones, with daily use, get scuffed or develop cracks to some degree. But a brand new phone sporting flaws is a problem, for sure. You may want to take your phone back to the retailer where you purchased it. You may be able to get a new one after an inspection. 

[via MacRumors]