I wrote about how I had in mind a loosely connected graph as the background of one of the pages I recently created. The idea wouldn't leave my head so I created a sketch of what I had in mind.
Oh! Right after creating this I came across another implementation that I like too.
Note that the first two above are dynamic so click on the links to see them in action.
I also really like this static image from The Brain Corporation. It shows the nodes as little disks, or spools like Tinker Toys, and the network shows depth in the z dimension. Nice!