(Updated with recent TED Talk by Pranav Mistry)

Forget cellphone cameras — future interfaces and the future web will be interactive projections. It could also mean the ultimate “convergence” of devices. For example, if the projection is simulating hardware — such as the buttons on your cellphone, a keyboard, a screen or watch interface — you could project multiple device interfaces from just one device, the projector. This could bring the cost of computing down even further, because interfaces become dynamic projections rather than physical objects. Perhaps a further stride against the digital divide?

It’s what Pranav Mistry from MIT’s Medialab calls “Sixth Sense technology” and it’s fascinating. His prototype device that makes it all happen is comprised of a pocket projector, a mirror and a camera. At this stage it’s bulky and crude, but imagine when the thing is small enough to fit on your glasses or is just clipped to your top pocket. The device is essentially a wearable gestural interface that augments the physical world around us with digital information, bringing the physical world and the digital world closer together.

Here is a recent talk, by Pranav himself (November 2009):

And then an older — the original — TED Talk, from earlier 2009:

(originally sourced here)