I usually blame some of the crazy things our family does on my husband; water slide playscape, jacuzzi pool with water pump, sledding/skiing behind 4 wheeler - he really owns these. But this Christmas, for the kids to get outside, I thought it would be really fun to have one of those huge balls to push each other around in. Not quite like the bouncing tire - a little more cushy, but the same concept.
I'll be happy to take credit for this one. :-)