One of the most famous, that is, "seen in the movies", Jewish rituals is the groom's stomping on a glass. Traditionally, at the end of the Jewish wedding ceremony, the groom breaks a glass, crushing it with his right foot, and the guests shout "Mazel tov!" ("Congratulations").
There are several meanings behind this custom. First, in Judaism joy is usually tempered with sorry and vs-a-vs. Thus the breaking of the glass brings a bit of destruction into the "building" we are doing together on that special day. Second, breaking the glass is a reminder that despite the joy of the day, Jews still mourn the destruction of the Temple in Jerusalem. Because of this, some Jews recite the verses "If I forget thee / O Jerusalem...". Third, the breaking of the glass is symbolic of the couple's breaking with their past lives so that they can create a new family together.