This is a great dictionary site for creative, "visual" people. This site allows you to diagram words and their associations to other words. It's a fun way to brainstorm! See formal description below:
Visuwords™ online graphical dictionary - Look up words to find their meanings and associations with other words and concepts. Produce diagrams reminiscent of a neural net. Learn how words associate. Enter words into the search box to look them up or double-click a node to expand the tree.