So I created the Family Memories tub:
I started off by purging the memorabilia so that I was truly only keeping the items that would matter 20 years down the road. I bought a pack of 12x12 plastic envelopes with a string closure at Michael's. Then, I cut out the year labels with my Silhouette Cameo (love). I made enough envelopes to last us well into the future. Everything now neatly fits into a single tub.
Along side the envelopes, I added in our family calendars - the ones we hang on the fridge and the ones I create each year for our family. This is the ideal place to store them so we can look at them in the years to come.
I need to go back to do the years prior to 2003 - the year my boys were born. I don't have as much stuff from those years, but I do have some stuff stashed away that I can sort into these envelopes for easier storage (and later retrieval). I'm sure this means I'll have to add another tub to store the items in, but I'm okay with that. Keeping these tubs in our storage area is much better than having everything take up space in my craft room.
What do you do with your long-term memorabilia storage?