One time, I spent hours wandering the parking lot after a concert. I really wish I had marked the location of my car and not relied on my memory to navigate. Next time I find myself in that situation, I'm going to use Find My Car Smarter. It's a Kickstarter project from FMC Smart which automatically marks your location every time you park your car.
The system uses a low-power Bluetooth Smart device (shown below), an iOS app and a Bluetooth 4.0 compatible phone like the iPhone 4S. The Bluetooth Smart device is a small USB dongle that fits in a standard car charger. It plugs into your car's 12V accessory charging port and stays there. The iOS app, Find My Car Smarter, connects to the Bluetooth Smart device and runs in the background
