I often use non-billboard/particle effects and run into the problem that they are only being rendered from one side.
It sure is great to have backface culling, but I don't like the way I had to get around it so far.
I've simply copied each face of the mesh and inverted the normals, causing twice the trianglecount.
Today I was wondering if I really had to do that. So if enabling two-sided rendering can be done easily, I'd really like to get the option to use it. (I think enabling two-sided rendering should be done by setting a flag in the settings of the mesh, i.e. in PCS2.)
If this is very complicated, or something you would rather like the material system to handle you can ignore this request.