Wikis are tools where students and professionals are able to collaborate and edit online content. They are an interactive place for videos, lessons, images, web 2.0's, links, and more. Users can contribute and edit from any place they are able access the site online.
There are two types of wikis that I have seen most often. One for classroom collaboration and one for professional collaboration...
I found a classroom wiki that I found to be very interesting (http://jabernethy.wikispaces.com/Classroom+Pets). Mrs. Abernethy includes blogs for students to give reviews (movie vs. books), share summaries and commentary using Storybird, Animoto, Voki's and more! This 21st century classroom shows how students collaborate and connect in very creative ways. I can see the work that the students have put into their responses in more than just linear writing, which allows students to connect to their reading, writing, understanding and communicating more richly. I found their collaboration and sharing of information inspiring. The site is chock full of blogs, student pages, wikis, etc.
The professional development wiki, http://yukon-education-mathematics.wikispaces.com/Literacy, is a connection between literacy and numeracy, with a focus on balanced literacy across content areas.
Good sites to visit for wiki inclusion ideas...
50 Ways to Use Wikis in the Classroom
Using Wikis in the Math Classroom