Bill Gates (when


that guy stepping down?) has demoed a vertical version of Microsoft's coffee table computer, the Surface, at the company's CEO summit.

Describing a future where cheap touchscreens will cover various surfaces in homes as well as offices, Gates said that he expects the technology to be "absolutely pervasive" in the near future.

Calling the Touch Wall, "new, risky and exciting", Gates told attendees: "Our view is that all the surfaces - horizontal surfaces, vertical surfaces - will eventually have an inexpensive screen-display capability and software that sees what you're doing there, so it's completely interactive", he told attendees at the summit.

The prototype Touch Wall, still at R&D stage, measures 4 x 6ft, and, like the Surface, uses cameras to detect touch.