One of my co-workers put this together for Why Day. It's a tiny bit of JavaScript with a backend on Heroku that allows you to store small bits of information without having to rely on the client-side. The major caveats are, I thought obviously, that it's not secure (Don't use this for passwords.) and that, unless you want to run your own backend, keys must be universally unique. I originally saw his post of it on Hacker News but I grabbed him after work today and asked him what his envisioned use-case was. He explained that, primarily, he saw it as a method of easy communication between frontends on different servers if you can't/don't want to set up your own server.