As I noted in my previous post on subjective sound quality, I primarily listen to my portable music players in my car. It's a 2010 Prius, and Toyota cleverly designed it to support portable music--under the armrest between the front seats, there's a small plastic container that's the perfect size to hold an iPod or cell phone, and below that platform there's an auxiliary input and DC outlet (cigarette lighters are so 1973) to plug it into. (You can see the set-up in the third photo in the "interior" gallery here.)
There's only one problem: the music controls on an iPhone or iPod Touch are not designed for driving. The pause, last song, and next song controls are the size of your fingertip, and you generally have to look at the screen to hit them accurately--not a good idea when you're speeding down the highway.
A new 99-cent app called PlaySafe is designed for just this problem. Before you start driving, you can select an album or playlist and turn shuffle on or off. As soon as you're done with your selection, the music starts playing, and PlaySafe overlays a simple set of controls on top of the touch-screen iPod. To pause (or resume playing), you touch a large arrow in the middle of the screen. To go back to the previous song, you swipe the screen to the left. To go to the next song, you swipe the screen to the right. Simple, elegant, and potentially life-saving.