I took mine down on Friday - after Christmas I want to get them out of the way; I'm fed up with the tree by then, especially when there are no pressies under the tree, it looks too bare.
6th January (12th Night) is when they are supposed to come down. According to superstition if you take them down before then you will suffer bad luck...and if you take them down afterwards you actually have to leave a decoration in place all year!
That must be why my mother still has her christmas cards on the mantelpiece in March. She has always left her decorations and tree up until my birthday on the 8th ;o)