Get out the photo albums and go over some family history with them. Even if it their history, stuff they did when they were 2, or what you were thinking in that picture. You can also get out the pictures of you when you were little and talk about your personal history to them. Kids love to hear stories about when their parents were kids, at least mine do.
I just did this with my 11 yr old when her little sister went to bed and we had some time for just us. What a nice time to spend one on one and reminisce about her being a little kid.
You can also throw in some scrap booking and turn this time into a crafting event. I so far choose to keep mine in an organized box. Scrapbooker I am not :o).
I think this afternoon while my daughter rides her pony I will take some pictures of them together and maybe come up with an alternative to the school pictures that I have yet to purchase.