Use Arduino-powered LED triangles to build an interactive display
In what can only be described as an outstaning use of the Arduino platform, Hyewon Shin, Eunjeong Ko, and Junsung Yi have designed and implemented hundreds of interactive and illuminated triangles powered by Arduino.
By using triangles, many different display types can be formed which are different than the usual squares - for example:
The triangles are 3D-printed and each contain a button and WS2812B addressable RGB LEDs. One Arduino can control several triangles, and the Arduinos are overall controlled by one master board.
Check out the results in the following video:
Absolutely outstanding and a credit to the creators. Learn how to do it yourself via the project page.
And if you're interested in doing this yourself, PMD Way has a you covered with a wide range of parts, such as: