Here’s a post I wrote this summer on moneysavingmom.com about Cheap or Free Toys for Kids. All the toys, except perhaps the duct tape, work about as well inside as out!
I read this similar article after I wrote mine. I totally agree on all his toy ideas. In fact, we gave our kids three huge empty appliance boxes for Christmas (as well as other toys, of course). They have so far used their boxes, or pieces of those boxes, in the backyard for: a fort, a stage for a concert, drums for that concert, to jump in as part of an obstacle course, as a table for a pretend cafe, and a slide. Nice.