First of all, uTable can be used as a usual desk. Users can put hands or arms on it, or place books, papers, office supplies or any objects on it, these actions will not affect the display. Usually, most of the touch sensitive table top systems lose the basic propping function of a table.

   When users want to point, or annotate, or even edit the content of the display, they just take up a special designed pen (called uPen) and point/sketch/write on the uTable. uPen is designed to be embedded with RF id so that it fundamentally supports multi-user task. Sketch will be recognized by a third part software. Though paper/pen metaphor is essential for table top systems, uTable can be used for multiple users at the same time. And the border of uTable is less then 3mm so that multiple uTables can be seamlessly combined into a larger one. The prototype system in the picture below is made up of 4 100cmX75cm uTables.

   When users look through documents or pictures, finger gestures are meaningful for interaction. Finger gestures based on multi-touch recognition are designed for selecting, creating, copying, annotating, deleting, moving, resizing and rotating documents. Gesture for delivering documents among multiple users is also supported.