The Rare Earth Magnets are also available at widgetsupply.com . For those living in southern ontario, "K-W Surplus" has a wide variety of these magnets, from tiny ones, about 1/8th" across, to larger 1" sq. (30lb capacity). The prices are also very good, starting at around $.50ea. I bought some of the large ones and the girl behind the counter handed me the large pile of them. She said, "Take as many as you want, I won't do it anymore, they hurt too much." They can give an awful pinch.

A note of caution with kids! Even small earth magnets, swallowed in amounts more than "1" can cause a great deal of damage. 2 medium sized magnets swallowed 20 minutes apart will send a person to the operating room!

And for those that can't find the amount of sticky tack needed, I'm sure that clay or unfired femo should work just as well. Even a scrap of leather would work, I expect.