You can get a list of high-yielding money funds from IBC Financial Data. Short-term corporate bonds and notes. Consider a two-year note issued by Lehman Brothers, the brokerage house. It's carries an A rating, which is extremely creditworthy. If you want a top-rated bond, you could consider the GE Capital bond that matures in March, 2002.
Bonds are IOUs issued by corporations.
They pay regular interest, usually twice a year. When the bond matures, the company pays you for the full face value of the bond. You can get somewhat higher yields if you buy longer-term issues. You'll have to buy the bonds through a broker. And, of course, there are utilities stocks.