Love the tables... mostly. It is so cool to see the kids turn to each other and actually start talking math. I almost wanted to cry that second day of Algebra 2 when I heard one student say "But don't you think the slope would be steeper if they were eating faster?" to his table-mate while they were doing these graphing stories. They were, by the way, a great way to warm the kids up and they really like the new big whiteboards (16" x 24"). Of course, the tables make it easier to communicate all the time, and there are kids with their backs to me, but I think the benefits outweigh the negatives.
The Watermelon in the Desert problem was pretty good for Geometry as a starter. The conversations were good, but how do you keep one student from monopolizing the solution? Actually heard one student say to his team "No, this is the answer, we don't need to talk about it anymore - You just need to agree with me." Of course I had to interrupt, but there always does seem to be those one or two who do the work, while the others are happy to sit and doodle watermelons on the paper.
I'm going to go plan something.