Case-Mate (http://www.case-mate.com/) has released the FUEL, an US$79.99
phone case and charger for the iPhone and Blackberry Bold. It charges
your phone’s battery while offering protection.

Built into the soft-grip holster case is a certified, rechargeable
lithium polymer battery. According to the folks at Case-Mate, talk
time, standby time, and internet usage are all extended by 2.5 times
for the iPhone and 1.5 times for the Blackberry Bold.

There’s an on/off button that makes the FUEL more efficient by only
drawing power when you need it. This is the first-ever holster case
with a built-in battery pack for the Blackberry BOLD, and the
first-ever holster designed battery case for the iPhone, according to
the Case-Mates.