Activity Post

I really enjoy doing an activity in class that makes them use teamwork and their math skills. I put 4 kids in a row. The first student has a piece on paper. I give them a problem or a series of problems. The work is passed back as each student does a step to it. I allow the student in front to critique the other student work. I do not use technology at this time with this activity. But the more I think about it I believe I could use a series of wiki spaces and let each group work and critique each set of problems. Then i could link the wikis and allow everyone to look and critique. We could do this once or twice a unit and they could use it to study for the test. Any others suggestions?