Microsoft chief executive Steve Ballmer unveiled what the company heralded as "the first in a new category of surface computing products" at an industry conference in southern California.

Microsoft Surface machines are built into tabletops and have 30-inch (76-centimeter) screens that can recognize objects placed on them and are controlled by touch instead of keyboard strokes or mouse movements, said the Redmond, Washington state-based company.

Unlike standard touch-screen computers, Microsoft Surface allows more than one person at a time to drag icons or give commands to allow collaborative efforts "just like in the real world," Microsoft said.

"It is one of those things you have to play with to appreciate how intuitive it is," said Directions on Microsoft analyst Matt Rosoff, who previewed the new computer.

The pricing and software of the machines are geared to business customers, according to Rosoff. Microsoft's Surface computers are priced at 5,000 dollars and up, the analyst said.

Surface computers have three-dimensional graphics and infra-red sensors for reading bar code labels.

For example, surface computers in restaurants or stores could identify bottles of wine by labels and provide descriptions of vintages along with video or pictures from the places they were made.

"The bottle of wine I order at the restaurant gets added to the tab simply by being put on the table," Rosoff said.

"At the end of the meal everyone puts their credit cards on the table and splits the bill by dragging icons to their cards."

Someone can place a mobile telephone on the table top and have the computer recognize them as well as access contents, according to Microsoft.

"With Surface, we are creating more intuitive ways for people to interact with technology," Ballmer said.

The surface computer is the brainchild of Microsoft's hardware and research teams.

In a move unusual for Microsoft, which traditionally licenses its technology to partners, the company is contracting to have the computers made.

Microsoft is initially targeting stores, hotels and casinos with the technology.

Surface computers will be available in some Las Vegas casinos, Starwood hotels and T Mobile stores by the end of the year, according to Ballmer.