SANTA CLARA, Calif. — Get your fingers ready.

Apple Inc.'s iPhone is leading a new wave of gadgets using touch-sensitive screens that react to taps, swishes or flicks of a finger. The improvements promise to be slicker and more intuitive than the rough stomp of finger presses and stylus-pointing required by many of today's devices.

Apple has already been showing off its finger ballet in video ads ahead of the smart phone's hotly anticipated launch on June 29.

Glide a finger across the screen to activate the device and main menu. Slide your digit up or down to scroll through contacts. Flick to flip through photos. Tap to zoom in on a Web site.

With Apple's marketing machinery, the iPhone is poised to become the poster child for the new breed of touch-screen technology, which relies on changes in electrical currents instead of pressure points.

But the iPhone will have rivals.

Shipments of this advanced strain of touch screens are projected to jump from fewer than 200,000 units in 2006 to more than 21 million units by 2012, with the bulk of the components going to mobile phones, according to iSuppli Corp., a market research company.

"This new user interface will be like a tsunami, hitting an entire spectrum of devices," predicted Francis Lee, the chief executive of Synaptics Inc., a maker of touch sensors.

Synaptics' latest technology is in a growing number of cell phones, including LG Electronics Co.'s LG Prada touch-screen phone that launched this year in Europe and South Korea and handles gesture-recognition similarly to the iPhone.

Apple does not comment about its component suppliers, and Lee declined to comment whether Synaptics is working with Apple on the iPhone.

"Touch screens are going to be more common, period, because rivals will slap them on to compete with Apple," said Michael Gartenberg, an analyst at JupiterResearch.

Even before the iPhone hype kicked into high gear over the past few months, touch screens in general were becoming more popular in cell phones. About 38 million handsets, about 4 percent of all mobile phones shipped in 2006, had touch-screen features.

But most touch-screen phones that shipped last year, including Palm Inc.'s Treo and Motorola Inc.'s ROKR E6, use "resistive touch" technology — the most common technology, said Jennifer Colegrove, a senior analyst of display technologies at iSuppli. It has two layers of glass or plastic and calculates the location of touch when pressure is applied with a stylus or a finger.

A more advanced screen, featured on the iPhone and LG Prada, uses "projected capacitive" technology. A mesh of metal wires between two layers of glass registers a touch when the electrical field is broken.

That's why light finger brushes will do the trick. But capacitive sensors don't even need actual physical contact: such touch screens already detect the proximity of a finger from 2 millimeters away, Colegrove said.

Cell phone maker Pantech Co. Ltd., for instance, has a flip-phone in which Synaptics' capacitive sensors are below the keypad so users can do finger gestures atop the buttons to navigate the phone.

The feather-like gestures possible with capacitive touch screens could feel more intuitive than the pokes needed on resistive touch screens that typically require a stylus or a fingernail to navigate. The screens are also generally brighter because their surface isn't covered with the thin film needed on resistive displays, Colegrove said.

But the iPhone is the only cell phone that can handle more than one finger at once, analysts say. That technology, which Apple has patented, allows users to resize a window, for instance, by pinching or expanding two fingers on the display.