If you haven't already lost your marbles, they can be used as part of this great project - a motorised swivel base perfect for monitors or large displays. The marbles act in a similar method to bearings between two surfaces, and a servo rotates the top surface. The servo is controlled by an Arduino board and use two potentiometers for base speed and position. Furthermore, the unit can be controlled easily by Bluetooth which then lends itself to be controlled by a custom Android app. You can see the demonstration below:
Even if you don't use Bluetooth and Anroid to control the base, it's still a great and workable project which lends itself to other forms of control. For example using an IR receiver and Arduino library would be very simple as well. For more information and details, visit here. To get started with your own base, consider our Freetronics Eleven - the Arduino-Uno compatible with low-profile USB socket, onboard prototyping space and easy to view LEDs:
