I just cut my leftovers into 2" strips and toss them in a Rubbermaid tote. I also have a tote for 1 1/2" strips (for the pieces that aren't wide enough to cut into 2").
I use those strips ALL THE TIME. For Christmas sales, I made 7 tablerunners and 2 babyquilts just from those totes. The totes don't look noticeably emptier, either. :oops:
I don't mean leftover yardage - just the odd pieces.