20 worthless pieces of junk: #5 -- The piggy bank

Not all piggy banks are bad, but the old-fashioned kind with one slot for putting in coins have had their day. "Think about it – what does a one-slot piggy bank ask a child to do? Save? I don't think so," says Susan Beacham, founder and CEO of Money Savvy Generation, a company set up to teach financial education to children. "Nowhere on a one-slot bank is the word 'save'. Ah, you say, it is implied. Really? Ask a child the next time he or she places a newly acquired coin in the slot why they are making that deposit. Get ready for a blank stare."

Give a kid a one-slot piggy bank and they may actually save when you ask, but Beacham's theory is that they aren't actually aware of what they are doing when they are putting money into that slot. And they have no concept why they are doing it or what they are saving for. The money goes in the slot and you get a blank stare.