[RedDevil]

My brother in law is an engineer who professionally works with neodymium magnets.
He also plays around with them at home for various purposes. He used to scavenge old hard disk drives for their magnets but now just orders them from Chinese and local web shops; a tenner gets you a wide array of supermagnets.

Two dimesized nickel plated neodymium alloy magnets attract each other so hard that you cannot normally pry them apart, but shifting them sideways does the trick relatively easily.
I found that if I lay one in the palm of my hand and stick the other to the back of my hand their attraction is already enough to keep them in place, even if I shake my hand about - and I do have rather big and thick hands...

Keep them away from kids. Magnets can kill when swallowed, especially when there is more than one involved.