While working on an installer for OpenStack I came up with the idea of implementing federation with the blockchain. The general idea is that federation requires identity management, payments and some standard way of deploying code in a trustworthy way. The blockchain gives you most of that, although the storage bits are probably better served by something like Ethereum.
I went around pitching the idea a bit toward the end of the year and got pretty close to raising a round. Being a solo founder and at least a few years too early probably didn't help much. I was in the process of converting the site to use container technologies when I decided to join a German company who is writing a container stack: https://giantswarm.io/.
The whole shebang is Open Source and I'm happy to answer questions about it, if anyone has them: https://github.com/stackmonkey/
.. and by "interesting", we mean of course "botnets."