Ian,
This is really exciting. I too was not aware of node-red until reading your first post although I have had a bit of experience with flow based programming:
http://www.fireflyexperiments.com/#home
@munnecke, your comments add even more interesting avenues to explore.
My original goal when I started working with Python and OpenSprinkler was to develop a platform for experimenting, and something that can be easily customized. I am now looking for ways to integrate node-red into the ospi distribution which has the possibility of allowing even more users to create custom functionality without having to learn all the details of hand coding a programming language.
Dan