TouchGraph is an on-line network visualizing tool that 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. It only works with URLs.
This is a graphical browser, for existing material (web sites), not a tool that you can use to build your own concept maps.
Price: Free to download a working demo; Academic $2,399; Enterprise $5999
Vic’s Picks are tools that Vic believes are significant and in the mainstream of mapping.