Visuwords

This is a cool online graphical dictionary that may interest people interested in words. It's absolutely free and pretty intuitive. Won't replace your other dictionaries but it may be worth playing around with a little.

From the site:

Enter words into the search box to look them up or double-click a node to expand the tree. Click and drag the background to pan around and use the mouse wheel to zoom. Hover over nodes to see the definition and click and drag individual nodes to move them around to help clarify connections.