It doesn't work with the 3D glasses they were handing out for free at the post office recently, but they did something tricky with their 3D - I have a hunch I know what it was, and I am going to experiment and see if I can get a picture that works with them.
I shot this one at .4 seconds, with an aperture of f/1.8. I took two pictures, each focused on the same point, but with the camera about 3" to the left for the second shot. Once I got it into software I applied a gradient map to convert it to black and white, then cut the red channel out of the right picture and pasted it over the red channel in the left picture.
To do the alternate one below, I had to cut the red and green channels and paste them over. It seems that standard 3D glasses are red and cyan, but the ones they gave out for the queen's visit were blue and yellow. Both were easy to replicate in software.