BumpTop- http://www.bumptop.com -aims to enrich the desktop metaphor with expressive, lightweight techniques found in the real world.
ideas about BumpTop, physically-based casual interfaces and pen-centric
interactions are outlined in the below CHI paper and Masters thesis. *
Anand Agarawala, Ravin Balakrishnan. (2006). Keepin’ it Real: Pushing
the Desktop Metaphor with Physics, Piles and the Pen. Proceedings of
CHI 2006 – the ACM Conference on Human Factors in Computing Systems. p.
1283-1292. (10 pages) * Anand Agarawala. Enriching the Desktop Metaphor
with Physics, Piles and the Pen. University of Toronto, Masters Thesis.