You're making it more complicated than it should be.
On most touchscreen phones, you 'touch' or 'tap' the relevent icon on the screen to get it to do what you want it to, yes? Like any touchscreen computer or other device. With the BlackBerry, the whole screen is like a big button, and you put your finger on, say, the Email icon, and press ('click') the screen to open the app. When I am typing, I am 'pressing' the keys, almost like a 'solid' keyboard, so you get the tactile feedback when you type a character.
http://www.engadget.com/2009/08/23/video-storm-2s-new-touchscreen-tech-explained-with-mindblowing/So, why cant they make the touchpad on a laptop 'clickable' using similar technology? Obviously, what you're doing appears on the monitor, rather than actually under your fingers, but surely the principal is the same?