Not all of our best experiments have been academic. Some of them have just helped us to keep the house running smoothly. After all, a lot of the time we grownups used to spend on housekeeping now goes into teaching, instead.
We have been particularly pleased with these laundry hampers that let even two- and three-year-olds sort their laundry. Sorting by color is good practice for them, anyway, and it makes wash day much easier.
This one is available on line from Organize-It. We bought ours locally.
We divide our laundry into White, Red, and Everything Else. We got white, red, and green mesh bags (the red ones we ended up buying separately), and it was remarkable how quickly the kids were able to pick up on the system.