From Nova Scotia, an article on getting future genealogists involved.
Simple three-generation pedigree chart using photos, color, stickers, whatever - instead of only hard facts. If they can write, have them add names and birthdates. Hang it where everyone can see it, take to "show and tell" at school.
Make a scrapbook page for each family member. Let the children decorate it (just keep a watch on spelling, dates and places).
A neat extension of this, says the author, is a series My Mother (or Father, Grandmother, Grandfather) and Me - A Memory Scrapbook for Kids (Kids Can Press), where kids enter data on a particular relative, compare lives, complete a three-generation chart and add photos. I haven't see this so can't judge, but I will look out for it.
Take the younger generations on vacations to the places important to you and your ancestors. Take pictures to use in scrapbooks. This brings family history alive.
The most important advice in the article: Keep "lessons" short and simple, so they'll come back for more!