A relay race where you hop across the room with a Valentines heart between your knees.
Stuffed Valentine's hearts
Divide the kids into two groups (if not even, have one child go twice). Give each team a small stuffed valentine heart. Have one child from each team place the heart between their legs and hop to the end of the room and back. They give the heart to next child in line, and this repeats until children have had their turn. The first team done is the winner.