[dude01]

Buckyballs! I still have some, bought when they were legal in the U.S. They're pretty strong magnets and stick together and you can make shapes with them.

Only problem -- if a little kid or animal swallows at least 2 of them, then they can pinch some intestines together inside you and be stuck there and kill you.

[shagie]

You can still buy rare Earth magnets of exceptional strength and small size. It’s just that they’re sold through scientific and industrial channels rather than the toy aisle at retail stores or marketed as toys online.