Microsoft has developed a horizontal user interface that allows users to manipulate data on the screen using their hands. Content can be dragged from location to location on the screen. Several people can sit in front of the screen and collaborate in new ways.
Microsoft's website lists four key capabilities that make it such a unique experience
Direct interaction. Users can grab digital information with their hands and interact with content on-screen by touch and gesture – without using a mouse or keyboard.
Multi-user experience. The large, horizontal, 30 inch display makes it easy for several people to gather and interact together with Microsoft Surface - providing a collaborative, face-to-face computing experience.
Multi-touch. Microsoft Surface responds to many points of contact simultaneously - not just from one finger, as with a typical touch screen, but from dozens of contact points at once.
Object recognition. Users can place physical objects on the screen to trigger different types of digital responses – providing for a multitude of applications and the transfer of digital content to mobile devices.
You can see a video of Microsoft Surface in action at http://www.microsoft.com/surface/Pages/Product/WhatIs.aspx.