So, lets say I have a class of 40 Natural Science Biology students. I put them into groups of 5. They are assigned a topic to write about, like stems cells or cloning or something science-y. I have each group start a Wiki. They can each work on the (collective) wiki from home, school, or wherever they can login to the internet. None of this "I saved the paper on my flashdrive and lost it," or "The paper is on my computer at home." Each student has a login name, and can access the wiki.
So, as the students are building the page, you (as the teacher) can review the revision history to see what each of the members have contributed. I hear all the time "So-and-so did all the work," or "So-and-so didn't help at all." This lets you know what REALLY happened! And, rather than a boring old paper, the students can build a multimedia presentation that can be shared with other students, and can become part of the student's e-portfolio to show potential employers.
If you would like to see the wiki I build, it's here - http://curriculumconceptmapping.wikispaces.com/ - and it's a few years old, so don't judge too harshly :) The story behind it is that there were three of us in a group for a professor's curriculum course, and he said we could make a project about the power dynamics of a classroom, and we could do it however we wanted. I had just learned about wikis, and I wanted to give it a shot. Instead of writing a paper, or doing a poster, we took pictures of how we saw the power dynamic working in this classroom, and we described them on the wiki. I was really the only one doing the revising and editing, but the finished product was unlike anything the prof or the class had seen at the time. The prof was so impressed, he shared it with the class.