christopherbaker.net has an incredible video of his email social network visualization. One of those ideas with a really simple concept with huge impact that makes me want to slap myself for not thinking of it first. Beautiful UI, I might add.
NodeBox is an amazing open source visualization tool for Mac OS X. It is basically a scriptable graphics tool, so you can draw things by using a really simple python code editor that's built into the app.
One of my favorite scripts uses the Web library to draw a graph of the hyperlinks between sites. It is rather basic in terms of its spidering capabilities, but I still think it has a heckuva lot of wow-factor.
The following hyperlink graph is actually for mediarevolutions.org (with a depth=3):
This page contains an archive of all entries posted to Media Revolutions in the Design category. They are listed from oldest to newest.
Decision-Making is the previous category.
Documentary is the next category.
Many more can be found on the main index page or by looking through the archives.
