Strip poker!!!
Everyone that wants to participate brings 25 2 1/2inch strips. You put six to 8 people on a table and let them play. We used cards and whoever drew the highest # won the strips. You play as long as you want or until you have played 25 games. It goes really fast and is real fun. They can bring red, green and christmas print fabric strips.
http://www.quiltguilds.com/games.htm
You can do Dirty Santa or White Elephant. Everyone brings around $10 of sewing stuff they do not want and wrap it up. Everyone draws a number and they take turns getting a gift or stealing a gift from someone else.
You can also do an ornament exchange.