Some projects can be simple and fun, and this one by Instructables user "The Nerdling" is no exception. They've used the Freetronics LeoStick as a simple "Awesome Button" - a project that randomly types a word via USB keyboard emulation into your PC. They have created a true minimalist version, by using a loop of wire as a normally-closed button. However with some work you could enclose it with a normal button and so on.
So what is a LeoStick? It's the Arduino Leonardo-compatible board that's cheaper and smaller than the original:
Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo which can be used a knock sensor and various tune and sound effects. Plus you can add extra circuitry with the matching protostick! For more information and to order, click here.