I just read an interesting proposal of adding to, or replacing, the internet with a network of pneumatic tubes to allow it to handle any physical object. This will require some explanation.
Before personal computers were common, large organizations like banks typically had a pneumatic network for exchanging paperwork. One would roll up the relevant paper and put it into a tube, and then put the tube into a slot. A vacuum would then pull this tube to its destination. One could exchange anything that fit into that tube through the network. So while the most common use was paperwork, one could also send keys, a packet of potato chips, or really anything that could be fit into the little canister.
Computers did away with pneumatic networks for the most part because of the difficulty involved. Setting it up was difficult. A preposterously complex network of tubes had to be built in the building, you had to have a dedicated routing room, because the vacuum only went one way, and you had to have really powerful pumps to abruptly suck the air out of any particular tube. So when personal computers became common, most organizations ran screaming from pneumatic systems. After all, the routing room had to sort who got what canister by hand.
I don't see a worldwide pneumatic system coming about without some serious automation of identifying and routing, because the internet has billions of nodes. The routing room, wherever on earth we put it, would have to be a nightmarish maze of pipes with many many OCR readers and supercomputers and robot claws for identifying the tube, putting it in the correct destination, and sending it on its way. No human being could ever hope to keep up. Hence the sheer insanity of this idea.