Christmas Crackers are a favorite tradition in England and contain a paper crown, a small gift, a motto or joke, and of course, the pop.  A Christmas Cracker is opened similarly to how a wishbone is divided - one person pulls on each side of the cracker and the person with the largest piece keeps the gifts inside.  More recently, each setting at the table is given their own Christmas Cracker to pull apart.  They are traditionally "cracked" after Christmas dinner.