I´ve had some stainlees steel tubes 20x30mm as scrap parts left, so we decided to build a tree out of it. It´s approx. 3m tall and 2,5m in diameter. Everything looks better with some sparkling rgb leds! A teensy running the fastled library is handling all the work. approx 750 leds are fastened to the tree. A Bluetooth app allows me to control the effects.