You should just avoid having people touch the screen while a 3D effect is being displayed And the way to do that is to never have a "touchable" 3D scene, i.e. never make the user touch the screen while it's displaying 3D. People might still try to touch a 3D object "inside" the screen, but that sort of people would also try to touch the little humans inside their TV.
I probably should have quoted his entire post, for context:
Wintrale said:
QUOTE(bandersnatch @ Jan 21 2011, 12:31 AM)
i'm also expecting tablets with 3D eventually, so theres that.