VisualComplexity.com has a rather interesting mission:

VisualComplexity.com intends to be a unified resource space for anyone interested in the visualizationof complex networks. The project's main goal is to leverage a criticalunderstanding of different visualization methods, across a series ofdisciplines, as diverse as Biology, Social Networks or the World WideWeb.

Some of these are pretty wild and really, quite beautiful. This Live Journalbased visualization maps members' social networks. Basically, you get to see who's friends with who.

It shows the friends and friends of friends of
any given LJ member. The user can simultaneously browse the networks of
friendship connections and interest matches amongst all these displayed
members.

Not sure what the practical application of something like this is, but it's certainly cool. It beats a Visio schematic.