A Tone Dialer is a tool used by almost all phreakers that phreak the pay phone systems. This is a tool that will produce tones automatically for you to play back into the phone system. These dialed tones may then be recorded onto a cassete or mp3 player and then later used at the pay phone system to get a free call. There are many of these dialers that are now available as software and some are becoming available for the Palm OS.
My tone dialer can produce tones from .00001Hz all the way to 100,000,000,0 Hz