I have taken my children out of their traditional rows and placed them into U's. I make two rows of U's one behind the other with a space in the center to walk through. I don't have any trouble passing out assignments; I just reach over the student in the front U to get to a student in the back U. Most students have a buddy on each side to help them with what they don't understand. Another benefit of this layout is that it opens up room in the middle of the classroom. This allows me to get closer to my students and provides more area for the students to do presentations.