[InclinedPlane]

That's an interesting point. With a $35 computer of those capabilities it's definitely a lot more doable to just develop out each hardware component to have a computer attached to it. You can run MongoDB or Couch or well as Node.js and have a services oriented architecture with high-level APIs between all your hardware components.

[domwood]

Exactly. Each device is potentially a self-contained unit of a whole, and things tend to get a damn sight more efficient if each is exclusively host to a specific tool, with the environment exclusively designed to match that specific tool. I do wonder just how efficient a cluster of Pis running a typical, but refactored for Pis, LAMP stack would be in comparison to a typical LAMP setup on a comparable server.