So "what to take with you" is the question every girl on the move must ask at one time or another. For me, it's a question of taking the ball or the box. Now before you question my choice in toys when we know there are some more glamorous things from which to choose, my favorite two toys right now are an empty diaper box and a baseball (soft one of course).
My solution: take the box to the ball so you can have both. Sometimes I walk the box and sometimes I kneel it, but either way gets me where I want to go.

