This 3D printed Jeep by Nicolas Roux, features tank tracks, and is controlled by an Arduino via an Android app over Bluetooth.
Sesame is a project that lets you open a door by simply saying "Open Sesame" into your smartphone or smartwatch.
The Arduino itself isn't really capable of playing music on its own, but add an Anniken Andee shield, and you're good to go!
Kerimil shows us how to communicate between Arduino and a custom Android app. It uses Bluetooth, and the MIT App Inventor for the app code.
An engineer from Ford has created a gear stick that shows the current gear, and vibrates when you should change, using Ford's OpenXC API.
The LightBlue Blue+ is a great little board, sporting Bluetooth, a battery, an accelerometer and a temperature sensor.
The BeagleBone Black is a Linux / Android / Arduino hybrid, sporting a 1GHz ARM processor, 512MB RAM and 92 connection pins.
The UDOO is a new prototyping board that combines the power of the Arduino, with a quad cored ARM processor, running Linux or Android.