From Apple PR:
Important Safety Notice
Today Apple announced the Apple Ultracompact USB Power Adapter Exchange program.
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.
The ultracompact USB power adapters were supplied with every iPhone 3G sold in the following countries, and may also have been purchased separately as an accessory:
US
Japan
Canada
Mexico
