You could do this but you'll have to modify the service managing the phone locking/sleeping yourself. The touch device should show up in /dev/input. If you want to suspend the phone (not suck up the battery like a vampire) you'll need to set up an interrupt from the touch screen as a wakeup source, I'm not sure if that's possible.
Note that the most recent kernel disables the touch screen during sleep, I don't know if that's possible to configure via userpsace.
Note that the most recent kernel disables the touch screen during sleep, I don't know if that's possible to configure via userpsace.