Microsoft (MSFT) launches its newest operating system, Windows 7, on Oct. 22, and one of the most-talked about aspects of the release will be its ability to support multi-touch applications.

Users of Apple’s (AAPL) iPhone may shrug. After all, they already use their index fingers to effortlessly flick through their contacts, and they can “pinch” and expand photos with their thumbs and forefingers.

But Windows 7 will enable users to simultaneously use all ten fingers on their screens, a capability that should unleash a new wave of cool applications–and ultimately change the way some consumers interact with their devices.

“We will start to develop a language between us and computers that’s very intuitive,” says Amichai Ben-David, CEO of N-trig, a private company that makes technology that is integrated into computer screens to make them touchable. N-trig, based in Kfar Saba, Israel, counts Microsoft as one of its investors.

Expanding the two-finger experience

Ben-David contends that there’s “actually very little we can do with two fingers” – which is how most iPhone users interact with the phone today.  During a recent visit to FORTUNE’s offices he demonstrated an nifty application that makes use of four fingers: He called up Google (GOOG) Earth and used the thumb and index finger of each hand to form a rectangle around the area he wished to zoom in on.  And he could use his two hands to keep zooming until he got the exact view he wanted.

He also demonstrated technology from SpaceClaim, a maker of 3D modeling software, that lets users manipulate images based on the number of fingers used: Two fingers, two index fingers, say, can move the image up and down on the screen, widen or contract in two dimensions. Add a third finger, and the image becomes a three-dimensional image that can be tilted, flipped and reworked with a 360-degree view.

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SpaceClaim is an N-trig partner, as is multimedia software company Corel, both of which are building what Ben-David calls “native multi-touch applications” — software that was designed with a multi-touch user in mind.

Ben-David acknowledges that the catalog of such native touch applications today remains limited.  In the meantime consumers may end us experiencing multi-touch when touch functions are glommed on to an existing application. N-trig itself developed the “hook” that turned Google Earth into a tactile experience.

“I don’t want to get into the politics between Microsoft and Google,” Ben-David joked, by way of explaining why Google wasn’t already making its products touch-friendly. He added: “Google will respond to multi-touch. Until they do, we will fill in the gaps.”

Google and software developers surely are waiting for computers with touch screens to go mainstream. DisplaySearch, an Austin, Texas, based research firm, estimates the touch panel touch panel market is on track to grow to $3.3 billion and 660 million units by 2015 – a figure that include mobile phones and so-called resistive-touch panels used in automated tellers and cash registers.  Ben-David says touch-panel PCs, notebooks and netbooks are coming soon from a variety of computer makers he can’t disclose.

Then again, touch isn’t for everyone: Silicon Alley Insider’s Henry Blodgett recently wrote a piece entitled Microsoft Windows 7? We Already Hate it.

His beef? Said Blodgett: “We never touch our PC screen, and we hate it when other people touch our PC screens.”