Touchscreen technology isn’t really all that new, but the popularity of Apple’s iPhone has whetted the public’s appetite for putting their fingers on the screen and doing things. But the technology that makes tiny phone screens react to touch would be prohibitively expensive on a screen even as large a UMPC, never mind the typical desktop’s widescreen.  HP and Microsoft use a different technology to track the movements of your fingers on a screen, and HP is planning on offering multiple touchscreen products