Bonnie was just on a recent episode of The Quilt Show (online) talking about this.
I call mine "jumpers"... because mine are just a little 1" scrap (call me a tightwad on thread! lol) ... and the scrap turns from being an "ender" into a "starter" for the next piece of my project. I have a little stash of these next to my machine in a tiny, cute coiled bowls made from clothesline.
I use jumpers as much as possible - it totally prevents the micro-thread nests that start from the short threads that are left from the previous "cut" if I use the thread cutter on my machine for the previous piece.
Sure cuts down on thread messes, dangly threads, etc... and saves loads of thread compared to using the cutters on the sides of machines.
That said, I don't have the brain cells to have another gazillion squares cut out and organized to use as the jumpers between the pieces of the work that I'm focusing on.