A pocket speakerphone adapter for a landline-based common telephone to provide the common telephone with speakerphone capabilities. The conventional handset of a conventional common telephone is disconnected from the handset jack of its base unit, and the pocket speakerphone is temporarily connected in its place to the handset jack of the base unit using a conventional handset cord. The conventional common telephone base unit provides interconnection with the public switched telephone network (PSTN), while the pocket speakerphone in accordance with the principles of the present invention provides a temporary adaptation of the land line common telephone to operate as a speakerphone.