Who's gonna pay for the specs?
It needs to be a paying or sponsored event, IMHO.
Could probably get the crew I'm working with in Sheffield to come down and do it here.
put on 3D specs
overlay red and green colourised copies of the same objects.
the further apart they move the more 'out' they become.
you'll see it as you do it.
To get nice (and less tiring for the viewer) visuals you need to separate the closer objects more than the distant ones, trivial if your rendering in 3d (just render from different camera positions, with slight convergence of the view directions) less so in pure 2d video projection.
If using 2 overlayed projectors I suspect simply not aligning the projectors perfectly might work to some extent, but would hurt the head after a while...
There are lots of options for stereo from the 'it works but looks crap' to the looks nice but costs a fortune...