Seems like this could be done with more respect for user/data sovereignty if done with Node.js. Essentially, you'd cat the file into the script, it would spin up an HTTP server, do some port knocking or whatever NAT-traversal-fu is necessary, then spit out a link with either your raw IP, or a preconfigured dynDNS domain name. This way we aren't carelessly littering our data all over the "cloud".
Know any port knocking as a service companies? If there was a reliable way to get a udp connection between hosts that I didn't have to write myself, I'd be tempted to take this on.
Are you serious?