Microsoft chairman Bill Gates this week took the wraps off Touch Wall, a 6ft x 4ft prototype screen based on Microsoft's Surface multi-touch technology.

Gates told attendees at the company's CEO Summit 2008 that affordable touch screens will adorn surfaces in homes and offices in the future.

The Touch Wall differs from long established electromagnetic-based whiteboards in that it detects hand or stylus movements using a camera beneath the screen.

"Our view is that all horizontal and vertical surfaces will eventually have an inexpensive screen-display capability and software that sees what you're doing so that it's completely interactive," said Gates.

Touch Wall is still in the research and development phase, but Gates said that Microsoft is already working out how to integrate the technology into future versions of Office.

"The Office group is thinking about what they can do in the next version that has built-in capabilities," said Gates.

"The Windows group is also building it down at the operating-system level so that any piece of Windows software will be able to have this type of interaction."