The larger your mortgage, the more dramatic the savings. On a $200,000 mortgage, you'll pay $255,088 in interest, plus the $200,000 principal, for a total of $455,088. Paying one-half your regular monthly mortgage amount every two weeks will result in interest of $194,430, a savings of $60,658. You'd have to earn at least $85,000 before taxes to net that much money.

Most mortgages can be pre-paid without penalty, but some mortgages in the secondary market (where many people with questionable credit have to go for a mortgage) have a penalty for pre-payment. Check with your lender.

You can achieve the benefits of pre-paying your mortgage without converting to a special type of mortgage or paying a fee. All it requires is discipline.