I once saw a tool that would graphically show what web sites are
linked to
a specific web site.  You could configure the number of hops away from
the specific web site.  The representation of web sites were shown as
boxes with lines drawn between them to indicate who is linked to who. 
You could navigate around the structure with the mouse. (I thought
this was a google tool, but I can't find it)  Could you please point
me to this tool?

Greetings, mthomas!

I believe that the tool you are seeking is TouchGraph.
http://www.touchgraph.com

"TouchGraph provides a hands-on way to visualize networks of
interrelated information. Networks are rendered as interactive graphs,
which lend themselves to a variety of transformations. By engaging
their visual image, a user is able to navigate through large networks,
and to explore different ways of arranging the network's components on
screen."
http://www.touchgraph.com/tech_overview.html

This tool allows you to drag the network of linked sites around with
your mouse.

Here is an interesting example using the Snopes Urban Myth Debunking
site
( http://www.snopes.com ):

http://www.touchgraph.com/TGGoogleBrowser.php?start=www.snopes.com


Search Strategy

Google links graphical diagram
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=Google+links+graphical+diagram&btnG=Google+Search


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I hope that this Answer provides you with exactly the information you
were seeking!

Regards,

aceresearcher

The website you're looking for is
http://www.kartoo.com/

:)
-Froogler

Somewhat similiar but not quite it.  The one I saw (I think I saw it
demoed on TechTV's The Screen Savers) let you use the mouse and could
dynamically drag around the web of urls.