Word Clouds

are a fun way to engage students. They can use them for all kinds of things.
www.wordle.net is a great one, but you can't save them. You can print them, though.

This one is from www.tagxedo.com
This one has a shape feature that allows you to manipulate the words into a shape that reflects your subject matter. For this one, I simply put the url for my techspot blog into the word load; it grabbed every word from my blog. You can set it to take out words like "and". Tagxedo also allows you to buy items with your cloud printed them.