This stuff is mind blowing — visualcomplexity has put together a “unified resource space for anyone interested in the visualization of complex networks”. There are a whole stack of different graphical representations of different types of networks.
Above is a protein homology graph (!?). More here.
The cool thing about this is that this hub of networks are so varied in their topics. Some of them are also flexible and interactive in their functioning (ie. they are not just a one off graphical representation). I think that I could play for hours examining the links between the various Fortune 500 companies, the Ivy League (and more) universities, and various research institutions at theyrule. (It would be good if you could get past employment histories and alumni linkages in there, too).Other networks that I found of interest were the Hudson Bay Food Web, this radial organisation chart, and the Blue Brain project which seeks to map the circuitry in the neo cortex (below).
The graphs from walrus are also stunning.
Now, network theory is not something I know very much about at all, although the bits and pieces I have come across over time are fascinating. I have a hand drawn map of the ‘social’ links in my network of friends that was drawn up over a few middies. Sort of like this one. One day I will make an electronic version so I can post it. Without names of course.
another update (16 January, 2006): It appears that the links to the images in this post have been recently updated, and so there are now different images appearing here. I don’t think that is a bad thing.