OtterBox has released the Defender Series case
( for
the iPhone 3G. It’s described as “semi-rugged, drop and scratchproof.”

The US$49.95 Defender is available in black and coming soon in white,
black/yellow and pink. It accommodates the iPhone 3G (both 8GB and
16GB models) with three slim-fit layers of protection, while offering
access to the silence switch, sync/charge, home, sleep/wake, volume,
camera and headphone jack.

Acoustical vents safeguard the microphone and speakers from dust and
dirt to allow clear sound transmission. The case includes a
holster-style swivel belt clip that converts into a display stand
when the device is inserted screen out.