In case your car isn't new or nice enough to have Bluetooth integration, this Steering Wheel Bluetooth Adaptor seems like the perfect solution, save for one catch.
Fitting around the inner part of a steering wheel with some options for size adjustment, the $US63 adaptor features a microphone and speakers (for speakerphone), along with an LCD display (incoming callers), SD port (MP3s), USB (anything) and FM-out (to play everything back through your car's stereo).
The catch, of course, is that the adaptor does need a power source, which happens to be your car's cigarette lighter. When you consider the logistics of connecting your steering wheel to a tether, no matter how cleanly, it can't sound like anything but a safety hazard...or am I missing some obvious precaution that makes this installation safe? [Chinavision via Newlaunches]