I’ve been playing with a site I just learned about called Visuwords. This site is an online dictionary/thesaurus with a twist. Just type in a word and it will appear in the middle of the screen. Keep watching as words that are related in some way (opposite, synonym, attribute, etc.) pop up with connecting lines. Mouse over the words and you’ll see definitions and associations. You can scroll your mouse to make the display larger or smaller and click and drag the connection map around.
There do seem to be limitations. I typed in the word mitochondria and got nothing. I typed in the singular form of the word, mitochondrion, and I got a hit. I think this could be confusing for students who are just learning the words. Otherwise, this seems to be another option for visual learners and possibly English language learners, as well. It is also a site that requires some experimentation to get the most out of it, so you would need to be sure that you had already gotten very familiar with it before you set your students loose on it.
If you really like it, you can even download the source code and host it on your own server. Let me know if you try it and whether you like it. What uses for this do you see in your classroom?