we aren't up to school years yet, but i also use all paintings for wrapping paper (alwasy get great comments about it). We give a lot oaway to grandparents/uncles/aunties so they have a treasure or two... throw the rubbishy stuff and memory book the rest.
mum kept some of our old writing books and the stories in there are hilarious... occasionally we'll rediscover them and read them to all the family, can barely get through them without dying of laughter! My brother had a very morbid imagination, to say the least lol. i plan on keeping the best bits like their stories etc but will turf the rest... probably... maybe lol.