I enjoy collaborating with others on a Wiki. I have used PB Wiki, now called PB Works, for quite some time. I utilized this website originally for a class in my Clarion Master's program and was put into a group in order to work on a project involving the creation of a school budget.
I became even more familiar with this site when I started one for our Cherub Choir at church. It was a great place to upload songs and lyrics for parents, and since I taught the choir with a friend, we could both have access to uploading material and schedules.
I could see how libraries can use this application for patrons' collaboration on reference materials and reviews of books. Teachers could likewise incorporate Wikis into their curriculum by allowing their classes to collaborate on the topics and content being taught. Patrons and students alike will enjoy the creativity involved with participating in a Wiki.