Last Friday I did this Andy Goldsworthy lesson with my son's class (check out all of the Duniway website's great lessons). We had a really interesting discussion while going through our slideshow, particularly over the question of whether the art installations, or the photographs, were the art (fourth graders can be profound, man!). Then we split up, went outside, and the kids got to work.
I thought their creations were breath-taking. (See some of Andy Goldsworthy's beautiful art here)
yipes! The link to Duniway's art lessons no longer is active - they have revised their site. If you are interested in the lesson plan, email me and I'd be happy to email you a copy.