Using an LCD’s poor viewing angle to your advantage 15 years ago
The works on even mac laptops
go to the demo page here: http://chrisharrison.net/projects/obliqueLCD/
look at your laptop screen from above and below (i.e., tilt or rock it) - not side to side.
More details here: http://chrisharrison.net/index.php/Research/ObliqueLCD