Let’s remember the first films that started to show the broad public futuristic communication scenarios, where users were able to exchange almost any kind of information to communicate with anyone at any place and at any time, like Marc Daniels’ “Star Trek” in the 1960s and James Cameron’s “Terminator” in the 1970s, for example. The consequence of this was that impersonalized spaces (e.g., airports) (Auge, 1992) could easily become a personalized environment for working or leisure, according to the specific needs of each user. These kinds of scenarios recently have been defined as ubiquitous communication environments. These environments are characterized by a system of interfaces that can be or fixed in allocated positions or portable (and/or wearable) devices. According to our experience with 2G technologies, we can foresee that the incoming 3G communication technologies will make sure, however, that the second typology of interfaces will become more and more protagonist in our daily lives. The reason is that portable and wearable devices represent a sort of prosthesis, and therefore, they reflect more than ever the definition of interface as an extension of the human body. When in 1973 Martin Cooper from Motorola patented an interface called Radio Telephone System (which can be defined as the first mobile phone), he probably didn’t suspect the substantial repercussion of his invention in the human microenvironment and in its social sphere. The mobile phone, enabling an interpersonal communication that is time- and place-independent, has changed humans’ habits and their way of making relationships (Rheingold, 1993). This system made possible a permanent and ubiquitous connection among users. At the same time, it has made users free to decide whether to be available or not in any moment and in any place they might be (Hunter, 2002). This article is based on empirical work in the field with network operators (Vodafone) and handset manufacturers (Nokia) and research at the Politecnico di Milano University, the University of Lapland, and the University of Brighton. The intention is to give a practical approach to the design of interfaces in ubiquitous communication scenarios.