Cut out construction paper hearts, and cut them in half each one with a unique jagged edge, or cut. Have enough heart pieces for everyone at the party. If the children are older you can cut the heart into 4 pieces.
Give each child a piece of heart, then have them find the child (or children) with the other pieces of their heart.
I like this idea – especially how you can adapt it for different age groups by how many pieces you cut the hearts into. I’ll have to suggest it for my girls’ school parties! 🙂