Why can't we have multi-touch on our PPCs? (I think it truly is possible.)

[ScrapMaker]

I'm not exactly sure how the iPhone does it, but we can do it too, I believe...

I believe ANY touch screen device can do it, aside from maybe the infrared ones...

When you push down in one spot on a resistive touch screen, and then push another finger down, it simply gives you the average of the two points... directly in the middle... so if you take the starting point, and the new average point, you can EASILY find out where the other finger was pushed down...

Clearly there would be limitations to this, depending on what information is available to the touch screen driver... but there are things like pressure/size that could work into the equation to make this work... if you move your fingers, the size between the two points would increase, and the average point would also move...

I just played around with a resistive-touch screen on my desk... for sure, the mouse cursor stayed exactly between my two fingers the whole time...

I honestly think that something like multi-touch can be done on our devices, even without a capacitive screen... hell, Apple might be doing something just like this... who knows what the iPhone's screen really "sees." It's probably just averaging things out, and using a formula as well...