In the Friendly Rest Room (FRR) project a series of paper sketches and computer implemented prototypes were designed to obtain information about user preferences with regard to the user interface. The first stages in the process were performed with the help of the user group, while later prototypes were tested in end user tests. The results point to the importance of a combination of visual, audible and tactile information as well as underlining the importance of incorporating real end users in the design process. In parallel to the user interface software design also a control program to steer the FRR prototypes was implemented and successfully tested in laboratory settings and partly also in real life environment.