This paper discusses new trends and directions in human interface (HI) technologies, and the effects of HI technologies on human life or on social activities. This paper postulates that the HI subsumes man-machine interface, human-computer interaction, human-human interaction, human-organizational interface, human-environmental interface, human-social interface, etc. A new communication model, called Human Interface Communication Model (HICOM), and a new human dialogue model, called Human Interface Dialogue model (HIDIM), are derived by reexamining trends and directions on HI technologies from the viewpoint of functional meanings of interfaces, and from the viewpoint of a socially distributed cognition mechanism.