This is not one of my usual foci, but it is a very powerful use of visualisation technologies which have been shown to enhance learning.
How do we get student to visualise the relationship between related terms when attempting to understand (fully) the nature of a concept. One more recent addition is the rather eye-catching VisuWords (http://www.visuwords.com/). Each colour represents a particular part of speech (nouns, verbs etc), while the arrows and their colours represent the relationships (synonym, homonyms etc).
If you roll-over the the words in circles, a small window pops up with more information. Try it and see! Besides being visually appealing, it also provides a better more engaging way to visualise the relationships that are part of the concept.