alleshannes.

by Ken Hinckley et al., Microsoft Research, 2004

Especially with mobile phones you have to struggle with the rather tiny screens. This problem can be solved: together! All you need are touch enabled devices, which can be combined via a sending and a receiving gesture. You could also imagine a cell phone showing its photos via a nearby tabletPC and so on.
Paper at Microsoft Research

Looking at RFID, each user could also have her/his personal pen, so that s/he can use any tablet around.

Social implications are interesting as well, as you can collaborate at a “virtual desk” without any further technical infrastructure neccessary.
Extending the idea into physical space, Miguel A. Nacenta et al. were researching a behaviour of the cursor across various displays, even if they are not next to each other.
A precedessor of this interaction principle has been developed by Hinckley as Tablet Whacking, which initiates the combination of screens by bumbing one into the other.
A whole lot of opportunities for (multiplayer) computer games, too!