I've been lucky enough working at Twitter to entertain a hobby project or two. My current obsession is "@mention constellations". Let me show you them:
What you're looking at is a small section of a larger graph showing Twitter users mentioning other Twitter users. Each vertex is a Twitter account. Each directed edge is a mention of one account by another. In this image you can see some accounts which get mentioned a lot (lots of inbound arrows to a central point) and accounts which do a lot of mentioning (lots of outbound arrows from a central point). The latter are mainly automata.
To me, in this presentation, the many distinct configurations look like galaxies. Or perhaps viruses. Can you recognize the basic phyla in this ecosystem? Some commonality, a lot of diversity; it's a menagerie of conversational molecules akin to the patterns one finds in Conway's game of life.
I'm working with GraphViz to produce these images, and I have hopes for Gephi although it's not there yet.