I've always enjoyed watching evolving technology and have wanted to incorporate some old tech into new projects, so I built Kalten a Nixie tube clock.
Nixie tubes were developed in the 1950's, a precursor to digital displays. It is a cold cathode electrode inside a glass tube filled with neon gas and just a touch of mercury. The numerical cathodes are stacked using ceramic insulators and when electricity is passed to the electrode, it reacts with the neon gas and glows, displaying the number.
There is still a small supply of these tubes in the Eastern Block countries, as they manufactured them into the early 80's.
I sourced the tubes from Russia, the board from a gentleman in the Ukraine, and then got to soldering.
The clock allows for 12/24 hour time display, date, and alarms. I placed RGB Leds under each tube and the color changes during use.
The case is built out of sheet metal and was finished in an antique/distressed paint theme.
Came out pretty cool, makes me want one for myself :)