Calling cards are basically personal business cards. Brett and Kate have written a nice introduction to calling cards. Time magazine also wrote a short piece talking about how they are coming back. Evidently the Marines art still using calling/visiting cards today.
It is a stretch to say the Marines still use them. When I reported for basic officer training, they made us buy them and we used them at a reception with the commanding general. That’s it. The rest of the military is too busy for victorian customs.
That being said, there is a need for non-business business cards. I had to make some up for the period between leaving active duty and starting my civilian job. They continue to come in handy when bumping in to non-business contacts while running about.