Use Wedding Bubbles!
I went to a wedding Saturday where we sent the bride and groom to their get away car in a cloud of bubbles. There were tons of extras, so a grabbed a handful and passed them out to the kids at my college girls' reunion cookout. Instant popularity!
These are children I don't see often, so it was a great way to start a conversation with them. The containers are perfect for smaller hands and if they get spilled, clean up in much easier. The best part: totally free!