remember one dirty trick to get more shades of gray out of the display that might work with the empeg too ...

Tricks are nice. However, I think this is atleast partially already in use. I belive the display is refreshed around 200Hz and I guess the brightness levels 1 and 2 (out of 0, 1, 2 and 3) are generated by having the pixel on only 50Hz or 100Hz, instead of the full 200Hz (brightness level 3) refresh rate.

If you have any moving scroll text or similar on the screen, you'll quickly notice that brightness level 1 and 2 are not good for anything that moves fast, because the refresh rate for those levels seem to be too low for fast moving areas. Though, they work perfectly on static or slowly moving image. I guess it would be possible to add even more brightness levels but I think they only could be used on static images.

One other way for achieving more brightness levels could be some sort of dithering patterns which might change every frame. But that falls more into the visualization/effect category and therefore wouldn't produce any additional grayscales that could be used on general level.

Kim