I have never been much of a fan of group work. The reason why not is a combination of my dislike on relying on other people for my grade and that I never seem to learn much in group projects, focusing most of my energy on trying to keep people getting along and on-topic. As a student studying to be a teacher, I also know that most students hate group work. It just doesn't seem like a good way of teaching.
That said, I rather like this Jigsaw Method, which seems like it would lessen a lot of the flaws in group work. For one thing, it increases the accountability of each student, making it impossible for someone to just sit back and let everyone else do the work.
One of my professors presented me with a hypothetical conundrum: how would I make Jigsaw work if I only had five computers? I'm inclined to have the "expert"groups meet at the computers, but then it seems like the old group scenario would kick in there, with one person running the computer and doing all the work. The major flaw with the jigsaw method, I think, is the expert groups. There, since they're all trying to find out the same information, each student's accountability goes way down again. Instead of a drive to research information for themselves, a student only has a drive to squeeze their expert group for information, then take it back to their regular group. Once again, only a few students end up doing the work of an entire class.
I think this could work if done with the right subject matter and some good classroom management, but I would always think twice about doing group projects.