Apple has issued a recall for the iPhone 3G AC adaptors in a number of countries.
“Apple has determined that under certain conditions the new ultracompact Apple USB power adapter’s metal prongs can break off and remain in a power outlet, creating a risk of electric shock. We have received reports of detached blades involving a very small percentage of the adapters sold, but no injuries have been reported.”

It effects every iPhone 3G sold in the United States, Canada, Japan, Mexico and several Latin American countries.
We are aware that this does not include any of official iPhone 3G devices sold in Saudi Arabia. But we don’t have an official iPhone 3G release here until now and many gray market iPhone 3G devices are already being sold here and if your iPhone 3G is from one of these countries then you need to get it replaced as soon as possible.