(I had this idea in June 2011 and wrote this post in Oct 2011, but I decided to wait with publishing until my lovely colleague Sylvia could get the scoop and use it for a marketing action).
A 3D display lets you experience 3D images by letting your left eye see something different than your right eye (‘stereoscopy’). Most technologies for this (certainly the ones used in cinema) use special glasses. Active/passive, based on colours, polarisation, timing… It’s fascinating, but that’s not what I want to address here. What intrigues me, are less common usages: what if instead showing something different to eye1 (left) and eye2 (right), you show something different to person1 and person2?