I have a number of little photography rituals with my family. Every year each kid gets pictures taken on their birthdays, for instance -- usually lots of pictures. It's evolved to the point where the pictures are an excuse for a new outfit. Middle Munchkin has been making her own outfits the past couple of years.
They each have a giant stuffed animal that we've taken a photograph with every year since they were born. These photos are all displayed in a single frame. I love these collections of photos. I love flipping through pages of my album and remembering each year, noting how the kid has grown but the smile remains the same.
One of my rituals is the summer family photo... only I'm not very good at getting this one done. Officially, I think I've managed to get maybe 4 or 5 photos since Munchkin #1 was born of the whole family together. There are probably a half dozen more where we quickly crowded together for a group shot, but nothing that fits the ritual of the summer family photo that I have in my head.