I'm going to have to write about "Wordle" - as my boss reckons it's the ultimate summariser. Feed it texts and it gives you a visual representation of the frequency and importance of each word in the text. You have to see a wordle to appreciate it.
This is an online tool, but it would be fantastic in a classroom - put a chapter of a book into it and see if the kids can predict the story - or get them to make up a story based on the wordle.
You could also use it to help kids with distilling the main ideas. It is also a great "art" activity - student can use public domain text from project Gutenberg to create art from poems and prose.
Very cool you will be looking for a whole bunch of text to put into the Wordle cruncher.