This week in all of our classes we are reviewing for exams. I decided to try a free online tool called Padlet that would allow students to collaboratively build review sheets (like posting stuff on a bulletin board or wall) that could contain text, images, links and videos. The students were assigned to groups and given guidelines as to how many posts, what was expected, and how they were going to be evaluated. They took to the project like ducks to water and didn't look up for 40 minutes.
You can see one such wall built in progress here.