The Parrot AR.Drone quadricopter was probably the coolest thing ever controlled via iPhone or iPod touch... until this. Dave Phipps has hooked up a '69 Pontiac GTO to his iPod touch -- he's been rebuilding these cars for a long time, and this particular one was picked up out of a farm for just $400. It's worth a lot more than that now, though, because he's replaced all of the wiring in the car and remotely connected it to his iPod, so he can start the engine, open up the doors, put the top up or down, and even control the radio all from the iPod touch.
There's a video of Phipps showing the system off after the break (sorry iPhone users, it's in Flash). He originally used Bluetooth, but now has the car set up on its own wireless network and he's got it working with a RedEye IR system, so he can even do macros and open all of the doors with one button and so on. He can't actually drive the car, but he can turn on the ignition, start the motor and even rev it up, all from the iPod touch. Very, very awesome.