3 Answers

I use a magnet to pick up a lot of straight pins, needles, or nails at one time.  I also use a magnet to attach something NON-magnetic to a magnetic  surface....a photo to the refrigerator door, for example.  Those magnetic key holders are useful in that a key or two fits into the little slide-open box, and the magnet helps you hide it on the car's underbelly, or under the BBQ shelf in the back yard. 

Fridge and car doors and hinges, computers, blenders, CD players, washing machines, escalators and elevators, credit cards, televisions, some toys, electric tooth brushes, and many more appliances. So if the world did not have magnets, just imagine how different the world would be. None of the things listed above, just to name a tiny amount.

Magnetic fasteners on jewelry are one of the best uses for me.