This paper provides a general approach to the problem of designing proper "interfaces" between humans and technologies at home. These interfaces should be designed for "all users", i.e. as friendly and simple to operate as possible, whatever the real technical background and/or motor ability of the user. The paper describes a philosophical approach and the consequent technical solution to these problems proposed in the framework of a European joint research project: the TIDE-MOVAID project (mobility and activity assistance systems for the disabled). The MOVAID approach is based on the assumption that all users are disabled when facing new technologies. MOVAID aims to provide solutions for interfacing all users, including the moderately and severely disabled, with their home environment. The general needs for simplicity and functionality of able-bodied and moderately disabled users are catered for by model friendly interfaces for standard appliances while the need of independence and autonomy of operation of the severely disabled users are catered for by a mobile manipulator robotic interface (the MOVAID unit). In the paper, the MOVAID approach and the prototypes of a novel friendly interface for a microwave oven and of the MOVAID mobile unit are presented in detail. Furthermore, the results of validation tests with moderately disabled users of the appliance interface are reported and discussed.