One time number

When you absolutely have to give out your contact information, and do not wish to be bothered by incoming phone calls after that particular business has been brought to a satisfactory conclusion, you would suscribe to this facility.

Your mobile phone service provider issues you with a number which will be valid only for a limited period of time. It is aliased to your original number (which you are careful not to disclose) and the number becomes unavailable after the set number of days or incoming calls.

This can be realised with existing technology by getting a second mobile phone and a second account, and throwing the SIM away when you no longer need that number. This is a technique to avoid the expense and hassle of carrying around a second mobile phone, as if one was insufficiently irritating to the public forced to listen to one side of the conversation as it is.