Do you have a garage? Fill them with different sizes/kinds of nails, screws, bolts, washers, cup hooks, eye bolts, zip ties, and any type of "fix it" supplies, and put them on a shelf. If they're located conveniently, you'll never need to repair anything because it acts like an insurance policy.

If the shelf is awkwardly high and just out of reach, you'll appreciate having nicely organized supplies as you balance on an upside down milk crate and lean precariously over random garden tools Final Destination style because you had a couple drinks and decided this was the day you'd finally fix that second floor window shutter that rattles loudly when it storms and the wind is just picking up so if you hurry you won't have to listen to it again.

haven't discovered what they're useful for, yet.

Store spices, sugar, salt?