For nervous investors who bug their brokers for stock and option prices (and feel guilty about it), U.S. Quotes has a remedy -- a service that provides quotations by touch-tone telephone. You simply call the company's computer and, when it answers, punch in your seven-digit account number. Then, through an easily learned code, you punch a series of buttons that asks the computer for individual prices. It responds with exact quotations as of 15 minutes earlier.

And that's not all. "Users can also program in and store their cost per share for any stock in their portfolio," adds Wayne Lemley, the electrical engineer who heads the company. "The computer will announce percentage increases or decreases from the investor's original cost."

The service, which began last March, lists stocks on the New York and American exchanges, NASDAQ over-the-counter issues, and options. An initial subscription fee of $45 buys from 6 to 12 hours' worth of quotes, depending on the time of day you dial the computer. After that you pay 12 cents a minute from 10 a.m. to 5 p.m. weekdays, or 6 cents a minute after trading hours. For information, call U.S. Quotes at (212) 687-7777.