>>950314Some current 3d devices exist that function by flashing back and forth between left- and right-eye images as quickly as the TV's frame rate would allow. The included glasses black out one eye at a time, sync'd to the TV's output, so that each image only appears to the eye it's meant for. On old 60 Hz TVs, this method was often too choppy, being slightly noticeable and sometimes irritating. New HD sets have 120 Hz capabilities, and performance in these is purportedly much improved.
tl;dr: Some 3d devices exist which don't require fancy polarizing displays.