The solution of using the ALT key with the letters works perfectly when dialing a number.

But what about once you are in the call, and the recorded message asks you to type letters? For example, typing the three-letter airport code after I call USAirways flight status. Or typing the person's last name when I am using employee look-up when I call a company? The ALT solution does not seem to work for that.

Any suggestions on how to deal with that?