Technological advances, miniaturization of embedded computing technology and wireless c- munication together with the evolution of global networks like the Internet have brought the vision of pervasive and ubiquitous computing to life: technology seamlessly woven into the "fabric of everyday life." Along with this development goes the need and challenge of int- faces supporting an intuitive, unobtrusive and distraction free interaction with such technolo- rich environments. Considering the huge amount, and ever growing number of a vast manifold of heterogeneous, small, embedded or mobile...