We describe POLAR, a portable, optical see-through, low-cost augmented reality system, which allows a user to see annotated views of small to medium-sized physical objects in an unencumbered way. No display or tracking equipment needs to be worn. We describe the system design, including a hybrid IR/vision head-tracking solution, and present examples of simple augmented scenes. POLAR’s compactness could allow it to be used as a lightweight and portable PC peripheral for providing mobile users with on-demand AR access in field work. Categories and Subject Descriptors H.5.1 [Multimedia Information Systems]: Artificial, augmented, and virtual realities; H.5.2. [User Interfaces]: Graphical user interfaces, Input devices and strategies; I.3.6 [Methodology and Techniques]: Interaction Techniques. General Terms Human Factors Keywords Augmented reality, optical see-through, portable, compact, lowcost, projection.