An interesting homemade display takes a different path than usual with surprisingly good results.
When it comes to building a display at home, you're typically limited to either a mechanical display or a matrix of lights. While it is theoretically possible to get to smaller scales, the equipment and technology needed to make something like an OLED or LCD aren't likely to be found in your garage.
Marin Davide had a really interesting idea on how to create a visually appealing display of a different kind. Instead of going mechanical or with a matrix of LEDs, the display of choice was a curved plate of thermochromic material.
The curved display in action
Looking at that image should give you a pretty immediate feeling for how this display looks. Bits of nichrome wire are mounted on the back of a material covered in thermochromic paint. When the nichrome wire heats up, the material changes color. The result is this very organic and visually appealing. Not only does it look great, but it is fairly simple to reproduce. The only real drawback to this display is the fairly slow refresh time. You have to wait for the material to cool down for something to disappear.