You may be asking why you need 10 point touch on a phone...The may be a little different...and more useful than you think.
- Today, most devices are limited to one or two point touch...meaning that if there is an unintentional contact with the surface when you are doing an activity like typing, the device averages that in, causing it to register that you hit the 'H' key when you meant to hit the 'J' key.
- It means that the device has a decent chance of knowing when your fingers have crossed paths. A major issue in direct manipulation applications.
- The device sees outlines, meaning that it can measure blob orientation. This mean that it can figure out when your right hand or left hand are interacting with the device, assigning separate modes to each hand.
The killer app for technologies like this is as likely to be interacting with the back of smaller devices a la Lucid Touch