My 9-month-old son has spent the last 15 minutes spinning the wheels of a toy stroller he flipped on its side. Before that he was "driving" a small yellow car with a bite-worn smiley face.

NEW YORK, NEW YORK - OCTOBER 26: Young girls from Brooklyn's Digital Girl Inc. were the first of 50,000 children across the U.S. to receive new Matchbox cars by Mercedes-Benz and Mattel ...