A collaboration system provides enhanced user interface to enable users to interact with electronic devices. In one embodiment, users can add content to a digital system by using a pen that streams coordinates so that input to the digital system may be based on conventional pen and paper handwriting. In another embodiment, a pie-based menu system is used for input to large display area digital devices in which an occluded portion of the pie-based menu system is not used for direct input by the user. The selection of which areas of the pie-based menu system should be omitted from use is adaptive and responsive to whether the user is left-handed or right-handed, and the wrist angle defined by the user's posture. In still another embodiment, an ergonomic open-shaped pie menu system is provided to facilitate selection of options on a digital surface.