IPhone 3G customers either have been or will be getting a text message on their better-behaved phones from Apple alerting them of a recall of the USB power adapter that comes with the phone. The adapter is a wall plug with the USB connector on the other end, so iPhone users can charge their phone from a standard power outlet.
Apple has realized there is a problem with these mini-adapters. The metal prongs can break off when removing the plug and remain in a power outlet, creating a risk of electric shock. There have been reports of the prongs breaking off on Apple enthusiast sites but so far, no one has been zapped.
Apple has already begun shipping replacement adapters with the newer iPhones. Look on the prong-side of the plug for a green dot like picture below. If you adapter has the dot, you are in the clear and do not need to go through the recall.
If not, then starting October 10, you have two choices: take the plug into one of 200 Apple retail stores and get a replacement, or mail it back to Apple by filling out an application on the Web.