David B. Lytle's family-owned business, Magically Magnetic, sells everything magnetic. Many of the products were developed by Mr. Lytle himself.
Dig into the site for products like the tiny, super-strong magnets pictured above, magnetic paint, and magnetic sheeting. The sheeting can be used as vent covers, as AT reader Sea shared with us. Just check out the photo at right.
(Thanks for the tip, Sea!)