I think this is a hard problem - a good tool for beginners would need to be amazing to get any uptake. The visual programming idioms that Ive noticed having so

I think this is a hard problem - a good tool for beginners would need to be amazing to get any uptake. The visual programming idioms that Ive noticed having some impact are things like dragging connection points to wire up inputs/outputs or behavior/function calls. If you look at modern visual GUI design tools such as apple/xcode Interface Builder, wiring components seems to be something that beginner users could understand easily. [Have a look at recent demos from 280 Norths Atlas to see this taken to the web] Maybe you could work with a school computer hobbies class as an ongoing project to see how they learn in practice - perhaps offer it as a visual logic puzzle?