There's a great app called The Brain on KurzweilAI.net. It shows a linked map of keywords that you can use to navigate through topics in articles on the Kurzweil site. There was a similar thing at the Millenium Dome and there's a French search engine with something similar. I used to have a huge sheet of paper on my wall where I mapped linked influences. I've recently thought about creating a web equivalent - would be good to link to the blog. I'll have to hunt the web to see if someone's done one already.
***Imported from old blog***