Boggle game. We used something similar at film-maker's camp for 10-13 year olds. Whatever film-making term they learned that day became the word to do a "boggle-like" activity eith. It went over very well.
Creating this into a worksheet might be something kids can grab for when they are done with work. Besides read a book of course! Or it could be used with dictionary practice to verify the words they write are really words!
Do you see it down there in the bottom right hand corner? Obviously this could be done with a printout or marker, but I just adore the use of magnet letters. It would make a great center, whole group or choice time activity.