Kathy over at ElecFreaks shares his DIY shake LED stick in the project log forum:
The principle of shake LED stick is based on that people have persistence of visual senses. When you light up a column LED at different moments in different ways, shake it, and a very beautiful picture will display before your eyes. It not only can display pictures but also can display characters, both static and dynamic. The pictures will be very nice. We can equip this kind of LED on our bicycles and fans, and other things. It’s good choice for DIY.
Via the forum.