ChEMBL

LinkedIn have a cool new plugin, that plots and clusters your LinkedIn connections, quite a nice illustration of biological network structure and complexity. It doesn't label the clusters for you, but it is easy to assign labels by just looking at a few nodes of each colour. One downside is that you need to have a pretty 'complete' profile in order to build the map. Almost certainly I gave the plugin power of attorney and complete access to all my finances in order to plot this, but it's a pretty picture.....

Update: The labels I gave were a little simplistic - the blue nodes are really scientific IT and software, the green nodes are better described as large pharma, and the orange nodes as academics/bioinformatics.