As I got asked quite often what you could do with these graphs I keep thinking about I have to post something I
read the other day:
Graphs visualising the structure of a website might be quite useful to understand the complexity or beauty of certain layouts. Thy are produced from the structure of the html code underneath the site you see, each tag forms a node and gets a link to it's father entity as well as to all subelements. Looks cool. This data then is thrown into a simple spring embedder (the visualisation part) and shown to you. Tata!
I like it. Play around and find some really sparse (mostly css driven) but interesting websites. Complex ones are everywhere and therfore boring though more colourful!