Toys!
schipman said:
If you want to wear out your boxer, take two empty milk cartons and tie them together with a piece of rope 4-6 fee long and place in driveway with dog. Rocky would attack on milk carton with would immediately cause the one on the other end to move. He would then attack the second one (because it moved so therefore must be conquered) which (you know what is coming) causes the first one to move so he then attacks it and back and forth and back and forth. He did eventually lay down between them with a look of defeat that was kind of pathetic.
Put the "game" away for a week and it will be a new adventure again next time.

And I thought I was savvy by just giving our girl a single empty milk carton to destroy. We've got to try this!
Seriously, most of the toys we give our girl are better than the store bought ones. Milk jugs, orange juice cartons, water bottles, yoghurt containers with stuff to lick left inside, sour cream containers with stuff to lick, cardboard boxes, her empty food bag, plastic sled, flexible flyer with pull rope, etc. The only store bought toys that are as good as these, if not better, are the grunting monkey and moo cow from bullysticks.com!