Dental floss
Cut soft cheese such as Brie, Camembert, or chevre by placing unflavored dental floss under it, crossing the ends over the top, and pulling.
Cake can be split horizontally into layers in a similar manner. Use a ruler to place toothpicks evenly around the cake to guide the floss, wrap, and pull.
Dental floss is also a good choice for stringing food-coloring-dyed or painted pasta "beads" (or any kind of beads) when kids need something "crafty" to do. Please note that dental floss is particularly strong and probably won't break if the kids try to strangle each other with it or their new necklaces, so this should be discouraged.
Potato flakes
Thicken soup, especially the "cream" kind, by adding instant mashed potatoes. Add it little by little and give it time to absorb liquid and dissolve before adding more if you particularly want to stay soup-ward of mashed potatoes with stuff in. I find this especially useful for commercially-made soups, because the potatoes also cover up some of the saltiness.
Scissors
Chop bacon with kitchen shears instead of a knife and cutting board.
Cut pizza -- especially the thin-crust kind -- with kitchen shears.
Spoon
Spread jam, jelly, and nut butter with the back of a spoon -- it's easier than trying to dig the stuff out of the jar with a knife and then keep it balanced until you get it to the bread.
Wine bottles
Pit cherries by placing them stem-end up on the opening of a wine bottle and pushing the pit out with the handle end of a chopstick. If you wash the bottle out first, you can then use the pits to make flavored water or vodka. Add sparkling water to the pits, give them a good swirl, and strain the water into flasses to serve, or collect a good pile of pits, add vodka and a few whole cherries, and infuse for at least a week.
