Using Wiki in Education Site 

List of Examples of Wikis in Higher Ed

The Science of Spectroscopy Wiki (used by several universities in collaboration)

Bowdoin College (USA) Wiki for English Class:  Romantic Audience Project

Stanford University Campus Wiki

LanguageLab Unleashed Wiki for Language Educators

University of British Columbia's Langugae Arts Wiki

 Student Using A Wiki for his thesis

Wiki Book Created by an Undergraduate Class

 and the professors' presentation on the experience

Undergraduate Computer Science Majors and a Spatial-based Wiki

Primary and Secondary School Uses

High School Online Collaborative Writing Wiki

Middle School Wiki for Class Studying Societies

Grade Nine English Class Wiki in Canada

International Teen Life Wiki, A Collaboration between Schools

Vicki Davis's Wiki for Her Students and Westwood High School

Vicki Davis and Julie Lindsay's Flat Classroom Project

 A collaboration between high school classrooms in Georgia and Bangladesh

High School Library Booklists Wiki

Booklists for high school students

Teacher Bud Hunt's Wiki

Unesco's Wiki on Open Education Resources

Wikieducator: "free eLearning content that anyone can edit and use"

Wikis Outside of Schools that could serve as Inspiration

Davis, California Commnnnity Wiki

Full Circle Associates Online Facilitation Wiki (lots of excellent resources here)