I came across this site with videos of all kinds that are not made for kids, but great for kids. I have not looked at many yet but they look great. I thought some of your kids (and you) would like these. One of the videos that I have had a chance to watch shows sculptures walking on a beach fueled by wind. The sculptures are made by Theo Jansen from the Netherlands. I wish I came across this video years ago when my ds was obsessed with building "things" with pvc pipes (and having to have water running through his sculptures).
http://thekidshouldseethis.com/post/9878478548
