Before you go throwing darts on Wall Street, check to make sure you can't earn a higher rate of return simply by investing in your own debt! For example, if you have a credit card balance that's costing you 19% per year, and you increase your payment, you will get a guaranteed 19% return on your investment.

What's more, your earnings will be tax-free! So use this JavaScript Calculator to see how much you could be earning if you increased your payment on any one of your debts. Instructions: Enter the current payment terms for any one of your outstanding debts, then enter an amount you could comfortably add to the payment. Finally, click on "Compute" to see what the return on your investment will be.