My best build so far is a computer. It is a modern communication device because we were studying Alexander Graham Bell. I learned that Alexander Graham Bell helped invent the air conditioner! He also created the basis for most modern communication devices!
I used redstone to make a computer with random lights on the screen. The redstone repeaters are used to make the lights look random and to keep the signals from crossing.
The torches just carry the signals from one level to another. The redstone clock creates the pulses. ~Samlitz