A nice tower with the common red and white spiral. It even has redstone lamps on top that can either turn on and off like a real rotating light or just leave them all on. Despite its' simplicity, it took quite a while to build because of trying to fit all the redstone in a small space within the lighthouse.
Feel free to use this in your survival world, server, map, etc. Use it as much as you want, no permission is required, and no credit is required, but would be nice.