Jack was asking for graphics. This is the best I could find to illustrate the metaphor in this latest version of my thoughts about hubjects. I like this image both for its sheer graphical quality, and for the fact that only the hub and spokes are visible. The wheel itself you can only guess.
Note : The Wheel and the Hub is now published under Mondeca namespace, including logo and copyright. The new URL is http://www.mondeca.com/content/download/455/3434/file/hubjects.pdf