Quote fishead soup
I've done something similar to that simple give the person a keyword such as Chistmas. They have to write as many words as possible that are related to that word. This is a good short activity. I wouldn't try it for the whole period.
An alternative to this is a game called Crazy IQ. Basically give them a topic (ex. Christmas, action verbs, colors, etc...) and individually or in groups, write one word from the given category. Give a point to each person/team that has a word that was not said. But if a word is duplicated, those teams with the same word don't receive a point.