Although my immediately family does not have any hardcore traditions for the New Year, I have seen a few of my family members throw a bucket of water outside at the stroke of midnight. I've also seen some of my friend's family do this sort of thing.
Apparently, the throwing out of water is to symbolize throwing out the old and dirty, to start the new year clean. According to some sources, it symbolizes the drive away of evil spirits.
(Does it mean something different for you and your family?)