Press your finger on a cell phone touch screen in 2007, and the screen could press right back. Immersion said Monday that it plans to license its force-feedback technology to handset makers, to make virtual buttons on cell phone screens.Fans of Sony\u2019s PlayStation 2 or Microsoft\u2019s Xbox are already familiar with the tactile reactions they feel in joysticks and steering wheels on their gaming consoles. Now the technology could move to mobile devices.Built into a PDA or smartphone, a haptic screen doesn\u2019t actually flex against a user\u2019s finger, but a small electric motor behind it delivers a small tap. Combined with an audible "click" feature used in platforms like automated teller machines (ATMs), the overall effect helps mimic a mechanical button on a digital screen.Immersion plans to license the technology to manufacturers of smartphones and PDAs who want to improve the utility of their touch screens, said Mark Belinsky, vice president of market strategy for the San Jose, Calif., company.The technology is similar to Immersion\u2019s VibeTonz System, which cell phone vendors already use to synchronize ring tones and video games with tactile vibrations.Samsung Electronics uses VibeTonz in its SCH-a930 mobile phone, allowing users to identify callers without taking a muted phone out of their pockets, since the phone vibrates differently for each assigned ring tone, Belinsky said.Samsung also uses haptic technology to add a sensory dimension to video games. Game makers including Punch Entertainment, SkyZone Entertainment and Sonic Branding Solutions have signed agreements with Immersion to use VibeTonz technology.In a demonstration at the IDG offices, a simple motorcycle racing game played on the SCH-a930 phone felt much more vivid when a reporter could feel the vibration of rough pavement beneath his wheels, the acceleration of a twisted throttle and the impact of a crash into a telephone pole.Vibrating songs and games are decent gimmicks for selling phones to kids, but the real payoff will come when vendors use haptic technology in their touch screens, said Avi Greengart, principal analyst for mobile devices with Current Analysis."If you\u2019re just trying to make a phone that\u2019s more exciting for young people, maybe that\u2019s exciting or maybe not," he said. "But when it comes to giving force feedback to a handset, this gives you the physical sensation that you just pushed a button, and that\u2019s compelling."As handsets get thinner and begin to host richer media, their designs feature "all screen and no buttons," Greengart said. The challenge for vendors is how to let users know which button to press, and which button they have just pressed. Tactile feedback is the best answer yet, he said.Immersion has licensed similar technology for years to manufacturers of video game consoles, medical training simulators and automotive dashboard manufacturers. The company is locked in a trademark infringement lawsuit with Sony, which allegedly uses Immersion\u2019s technology in the PlayStation series.-Ben Ames, IDG News Service (Boston Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.