tabletopguidelines
System Guidelines for Co-located, Collaborative Work on a Tabletop Display
Scott, S.D., Grant, K.D., Mandryk, R.L.
Proceedings of ECSCW'03, European Conference Computer-Supported Cooperative Work 2003, September 2003
Collaborative interactions with many existing digital tabletop systems lack the fluidity of collaborating around a table using traditional media. This paper presents a critical analysis of the current state-of-the-art in digital tabletop systems research, targeted at discovering how user requirements for collaboration are currently being met and uncovering areas requiring further development. By considering research on tabletop displays, collaboration, and communication, several design guidelines for effective co-located collaboration around a tabletop display emerged. These guidelines suggest that technology must support: (1) natural interpersonal interaction, (2) transitions between activities, (3) transitions between personal and group work, (4) transitions between tabletop collaboration and external work, (5) the use of physical objects, (6) accessing shared physical and digital objects, (7) flexible user arrangements, and (8) simultaneous user interactions. The critical analysis also revealed several important directions for future research, including: standardization of methods to evaluate co-located collaboration; comparative studies to determine the impact of existing system configurations on collaboration; and creation of a taxonomy of collaborative tasks to help determine which tasks and activities are suitable for tabletop collaboration.
http://graphics/~dphan/downloads/tabletopguidelines.pdf

iStuff
iStuff: A Physical User Interface Toolkit for Ubiquitous Computing Environments
Rafael Ballagas, Meredith Ringel, Maureen Stone, Jan Borchers
Proceedings of CHI 2003
The iStuff toolkit of physical devices, and the flexible software infrastructure to support it, were designed to simplify the exploration of novel interaction techniques in the post-desktop era of multiple users, devices, systems and applications collaborating in an interactive environment.  The toolkit leverages an existing interactive workspace infrastructure, making it lightweight and platform independent.  The supporting software framework includes a dynamically configurable intermediary to simplify the mapping of devices to applications. We describe the iStuff architecture and provide several examples of iStuff, organized into a design space of ubiquitous computing interaction components. The main contribution is a physical toolkit for distributed, heterogeneous environments with run-time retargetable device data flow. We conclude with some insights and experiences derived from using this toolkit and framework to prototype experimental interaction techniques for ubiquitous computing environments.  
http://graphics/~dphan/downloads/istuff.pdf

virtualdesktops
When One Isn't Enough: An Analysis of Virtual Desktop Usage Strategies and Their Implications for Design
Meredith Ringel
Extended Abstracts of CHI 2003
Screen space is a limited resource for computer users multiple monitors are one means of workspace expansion, and virtual desktops are yet another way to increase screen real-estate. We present a taxonomy of organization strategies based on our observations during a series of interviews with virtual desktop users. Additionally, we explore causes of varying user preferences for physical versus virtual means of screen-space expansion. Finally, we discuss the design implications of our findings.  that their mappings of windows to particular virtual desktops were remarkably consistent for individual users over time. We also learned that many users did not view virtual desktops as a cheaper and less optimal solution than multiple monitors, but rather that they preferred to use virtual desktops in some situations and multi-monitor setups in others.
http://www.stanford.edu/~merrie/papers/vmon.pdf