I use those to keep my marking pencils, quilting attatchments for each of my different machines, or other notions in. I picked up a bunch last year after back to school season and everything was on sale for like a quarter each. I also bought the zipper pouches for pencils that are see through and use them for my safety pins. They don't take up much room and can stand on end in a basket.
I will have to try the thread thing. What a great idea.