This full paper was submitted and accepted at the British HCI 2005 conference in Edinburgh. The paper - Mixed Interaction Spaces - Expanding the Interaction Space with Mobile Devices - describes how the MIXIS concept is implemented and discusses four applications build on top of it. The paper is written by Thomas Riisgaard Hansen, Eva Eriksson and I.

Abstract
Mobile phones are mainly interacted with through buttons, thumbwheels or pens. However, mobile devices are not just terminals into a virtual world; they are objects in a physical world. The concept of Mixed Interaction Space (MIXIS) expands the interaction with mobile phone into the physical world [Hansen et al. 2005]. MIXIS uses the camera in mobile devices to track a fixed-point and thereby establishes a 3 dimensional interaction space wherein the position and rotation of the phone can be tracked. In this paper we demonstrate that MIXIS opens up for new flexible ways of interacting with mobile devices. We present a set of novel, flexible applications built with MIXIS and we show that MIXIS is a feasible way of interacting with mobile devices by evaluating a MIXIS application against a traditional mobile interface. Finally, we discuss some design issues with MIXIS.

read the entire paper in pdf here