I connected a receipt printer to the internet in an early exploration of person-to-place messaging. Why is this useful? Well, often I have some short bit of text on my computer that I need with my when I run out of the house. I can never find a pencil to write it down, so now I can just paste it into a webpage, hit print, and it comes out on my receipt printer!
This is the first really interesting thing to come out of my explorations with a receipt printer I bought on Ebay. Originally the PCB I designed ran it’s own server, but then I changed it to talk to a web-based server.