So, my idea is very simple.  I believe that it would be benificial for walls to be able to be placed every pixel.  (Not be one pixel thick walls); to just be able to place them more freely.  For example, you can currently only place walls every four pixels.  I think it would help if you could "stack" walls, to place them more freely, so you could place them every pixel.  I understand that this borders on the one-thick walls topic, as it would mess with the simulation, but it would be a very posative change.  It is just hard to have to work around the wall positioning, and I believe many people would benifit from walls that can be built around an object, and not the other way around.