Magnets are incredibly useful. They record data, allow bullet trains to go at insane speeds, and hold coupons to the fridge door. The only problem is if you have any sort of metal in your body: then you're not quite such a fan of magnets.
Fortunately, science has your back: they've invented the anti-magnet.
It works like this: magnetic fields will interact, as anybody who made it out of fourth grade science knows, and it's pretty hard to stop this. Magnetic fields are pretty good at reaching out through even thick barriers. It's especially problematic for people with, say, a pacemaker or a hip replacement who need an MRI, since the magnets can literally rip the implants out of your body.
Basically, it works like this: two outside layers hold eight layers of a superconductor. The superconductor blocks any magnetic field from either side of the material while also preventing any distortions of a magnetic field on the other side of the material. In short, you can put two strong magnets next to each other and they'll act like nothing is there.
So, it's neat, but what's the big deal? Well, it would allow magnetic media, like, say, every hard drive ever, to be put close to strong magnetic fields with absolutely no problem. It would make getting an MRI substantially easier for people with implants, that is, old people who need MRIs. Military ships could use the stuff to avoid mines that trigger in the presence of magnetic fields.
In short, it'd change a lot in the world for the better. Now they just have to actually build it, but, hey, there are challenges everywhere.