You have the option to accept the new call or not. Regarding outgoing calls, you can use MyLine instead of a calling card at payphones at substantially less cost than a calling card or other alternate billing. What you do is dial your own 800 number. The passcode can be changed at any time in the options menu. When you enter your passcode, the greeting stops and you go immediatly into maintainence mode.
International callback is another feature.
From a foreign country you may wish to make a call to the USA, at USA rates. You dial into MyLine using the POTS number associated with your 800 number and you request a callback, either immediatly or at some future time. Wakeup calls is another feature. Tell MyLine to wake you at a certain time and it will ring your phone as requested. You respond by entering your passcode to let it know you are awake.