Graph visualization is a powerfull means to find relation between data and cluster them (It is one of my favorite method). Touchgraph is a online visualisation tools that allows to generate a graph from a query you made. It is a java plugins that work right into your browser.
Currently Touchgraph work with:
I found the rendering very impressive and the integration with facebook photo totally cool (see the screenshots). However you can’t use it 
on your own data. It could be a killing application to add to a publication list or even blog post. Imagine the ability to navigate visualy between posts. Well it will come one day, I just don’t know when 
If you want to try your own query, just go to their web site: TouchGraph | Products: Our Technology
Ps theses guys rocks they use game theory as amazon example
Microsoft have released the RC of its Entreprise search v2008 software. A free version (the express one) is available but restricted to a single server. It is based on the sharepoint 2007 software. Price for the microsoft solution remains unknown. See the annoucement here :Enterprise Search from Microsoft. Microsoft is not the first to offers search engine for enterprise. Google is already on the market with Google Mini and Google appliance.
IBM and Yahoo have also a product called IBM Omnifind Yahoo! which is free. It is tailored to search up to 500 000 documents. I found the welcome message leaved by the team on their blog to Microsoft to welcome them on the market is pretty funny.
Here is some screenshots
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