A small group of us at work were discussing New Year's traditions over lunch yesterday, and I was curious as to the traditions of the posters here.
At new year's (the actual day) my family gets together to eat a lot of food. =P
In the Japanese tradition to have good luck all year you must eat mochi soup first thing on the start of the new year. I have a bowl of it sitting next to me as I type this (got up a bit late =P). My grandmother likes to stack the deck, so this year we also have black-eyed peas, since I'm told it's a Southern tradition that you must eat one black-eyed pea for each day in the year to have good luck the whole year 'round.
Mainly we use this as an excuse to cook a lot of good food (sukiyaki, tempura, gobo, wontons, sushi, mochi, etc), but it is rooted in tradition.