Eric Blue has assembled a valuable list of about 30 reference links and examples of information visualization in his post, Dataesthetics: The Power and Beauty of Data Visualization. I especially liked the http://infosthetics.com/ reference. Across the board, these links provide a pretty compelling showcase of what approaches and techniques can be taken to effective data presentation.
For example, as one of the many hundreds of options available, here is Sun’s interactive Java concept map (will spawn a new window and requires Flash viewer):
I highly recommend Eric Blue’s posting.