Failure to see applications is a failure of imagination. Also, Cassandra is highly optimized for extremely fast write rates at large scale, not read-only. Cassandra also has no SPOF, includes variable consistency guarantees, and many other great features. Specifically focusing on the fact that it can have 2 billion columns in a row glosses over a number of other things, but that hardly denormalized or non-transactional databases have few applications.

I use a branch current monitor from PowerLogic (BCM42) coupled with a Barionet-50 to perform monitoring of every circuit in the house simultaneously. Some details can be found here:

http://blog.insidesystems.net/modbusrtu-via-tcp-serial-gateway-with-ruby

The kinds of analysis you can perform with this are tons of fun. For instance, how much does that desuperheater in my geothermal unit really help the water heater? Has a lightbulb in one of my floodlights gone out? Did somebody leave the refrigerator door open? Has the water softener stuck again causing the well pump to work overtime? This approach lets you monitor WAY more than just consumption.

I don't know that one needs to be as specific as neural prosthesis, but nearly every human on the planet is augmented in some way from the natural state, be it a pair of glasses or contacts, clothes to augment the insulating properties of skin, umbrellas to keep the rain off our heads, or air conditioning to stay cooler in warm climates. It seems that many people who refer to cyborg-like physical augmentation don't have a clear distinction between what would be considered a 'tool' and what would be considered an augmentation.

My personal opinion on the matter is that it is both impossible to define the distinction without being able to come up with exceptions on either side and not currently a relevant question to ask. I believe that if technology becomes so advanced that it is impossible to distinguish between a human with machine bits added and a machine with human bits added, the distinction will either not matter, or be readily apparent.