This is an idea that I actually came up with on my own years ago while living in Colorado (without the Internet for inspiration). I don't remember exactly how it came to be a memory crate, but it did. I know I purchased the crate because I loved it, and somehow it became my memory crate.

I have two now, but need a third because the two are overflowing and have my eyes looking for the next one. Sure, the crates are all over the place, but sometimes those antique shops want outrageous amounts of money for something old that they probably got for free anyway. I have my own arbitrary pricing system in my head and if something doesn't fit into that system on a particular day, then it stays at the store.
I did find a great deal on one at a garage sale when I was in Washington last year, but it now hangs in my daughter's room waiting to be filled with important mementos of her life.