Interactive, online tool in which students can create webs for a variety of reasons such as brainstorming, essay writing, reading comprehension, etc. I just used it to create a 'To-Do' list, can be utilized effectively for a variety of things.
This is a great website, with lots and lots of links to fantastic educational websites all around the world wide web. You click on a topic, and it provides a list of websites that have information about that topic.