Yep. Rainbows here too.Normally on my computer it's around a -45° axis both lenses go dark. On my digital camera (older) Polarized lenses go "dark" around 90° even.
@kronin323 I believe mentioned the orientation won't be the same in every device, but should be the same in both lenses!
One last note, has anyone else noticed this only seems to work with the light traveling one direction, if you flip them over I typically get all types of weird "rainbow" or interference effects. @SiRacer420