The folks at LittleSis (the opposite of Big Brother) have just released a nice tool for creating “powermaps” using the relationships between entities in their database. Powermaps are an informal term for a type of network graph illustrating various types of relationships between (often multiple types) of people or institutions
The maps are quite lovely, built as zoomable SVG objects embedded in the webpage with elegant highlighting and mouse-over label reveals. The entities on screen supporting clicking through to the corresponding page in the LittleSis database. From peeking at the Oiligrapher source code on github it appears that the tool makes heavy use of d3 (of course) and some of the force-directed network layout code. They cite Mark Lombardi as a strong influence for the visual aesthetic. Not sure about speed/performance issues on larger networks, but this seems like a great tool for these types of relatively sparse illustrations.