MessageProbe (by Hutchinson et al, 2003)

The messageProbe is a simple application that enables members of a distributed family to communicate using digital Post-It notes in a zoomable space. It can function synchronously, with two or more family members writing and drawing from different locations at the same time, or synchronously, with family members checking it periodically for new messages from other households. There is no mouse or keyboard – just a writable LCD tablet and pen.

Source: Hutchinson, H., Hansen, H., Roussel, N., et al. 2003. Technology Probes: Inspiring Design for and with Families In Technology Probes. ACM Press, New York, NY.
http://hcil2.cs.umd.edu/trs/2002-16/2002-16.html

Technology and Artifacts | UX-Relatedness