Back in April, Durring some time off on a work trip, I was able to spend some time in Frankfurt, Germany. One of the placed I wanted to check out was the Museum for Communication Frankfurt. This museum is located in the Museum District and is right off the Main River.
It featured many retro communication devices as well as some future ones as well. Some of the cool items to check out were the fully operational vintage telephone switchboard that uses relays to connect the call. On the roof of the building there was a Ham radio shack with a ham radio operator and answered any questions you had. The operator on duty that day was telling me that sometimes they can reach New York from their roof.
Also on exhibit was a fully functional mail sorting machine that would scan the envelope address and route it to the proper sorting bin.
I wish I would have captured more photos of the museum, but I was unsure of their photo policy when I was there. I will tell you that the Staff are very helpful and all spoke good english too. If you ever make it over to Frankfurt, I would definitely add this to your list of things to check out.