I have an irresistible urge to purchase both an iPhone and a badass model airplane after checking out the iPhly. This device/app developed by Ari Krupnik lets you control a remote-controlled vehicle using your iPhone.
The iPhly has a special case that lets you tune into your device's frequency and a custom app that lets you control it. The controls are easy enough to learn: turning the plane can be done by turning the iPhone, making the plane climb or descend can be done by bringing the phone up and down, shaking the phone kills the engine and swiping the iPhone's screen lets you move the plane left and right.
iPhly works with boats and cars and is currently being sold for $99 for just the case and $139 for a case and a frequency module and receiver. Hopefully this device encourages people who were formerly put off by the big and bulky controls of R/C vehicles to give things a second go. I know I am a lot more open to earning my miniature wings now than I was before.