So what is the point about portable projectors?

Well the crucial element is the synthesis that mini projectors provide with miniature computers to make at tiny computer. Imagine a cellphone size computer standing on the table in front of you, projecting an image onto the table, as your workspace, and you writing on that workspace with your stylus/pen with either hand writing recognition or on screen keyboard. Using an onscreen keyboard I can even foresee touch typing with the typist finger movement being recognised for those with 'legacy' QWERTY training. This is all possible now (2007) in prototype form and looks set for limited release in 2008. What is it going to be, it will be a miniature computer with a virtual screen and a virtual input device all in your cellphone (or other convergence device). Another interesting video along these lines is the Movable Displays.

What can a portable projector offer us. Think of augmented reality. This is a little harder to grasp but will have a much greater impact. Think of the "heads up" in fighter plane's cockpits and the recent arrival of similar technology into cars (eg BMW). The developmental work which is partially shown in the video on Handheld Interactive Desktops, is that you can get a mobile projector to recognise its surroundings, then display on the surfaces, messages relating the environment. For example, a wall power socket, recognised by the device would project onto the wall beside the device text and images explaining about it, describing how to fix it, or any other context sensitive information as may be appropriate.
Where can this go? We apart from simplifying manual and tech support, it is really also the fore bringer of 'heads-up' displays built into sunglasses!!! The camera in the glasses will sense its surroundings and add in augmented visual information projected onto the inside lense of the glasses. One immediate use I can see for that would be for colourblind people to be given the ability to detect Red. The question is, what other information would we choose to receive (in the privacy of our own glasses) on top of the real world.