I need ideas for using up my leftover box of hardwood flooring.

Personally, I would save those bits in case you ever have to repair the floor due water damage, a deep scratch..... you will be glad to have the extra wood for repairs.

save them

I agree with Sharon BUT if you have a wall you'd like to accent use the wood, placing it at angles like a chevron pattern. Be sure toclean the wall first with a vinager & water solution, let dry for 24 hours and proceed, gluing wood strips in place. Its beautiful and very effective over a fireplace.

Bottom of cabinets to save the bottom from cans & pots & under sinks.

I would keep in the vent of damage or such. One box is not much to keep.

Make a table top