I add this to the Code archives. It containes the pretty fast grass we have alsready seen some time ago, plus a function to create very fast trees / forest patches, and kinda experimental volumetric fog FX.
http://www.melog.ch/dl/forest.zip
Maybe you need to use an other skybox if you do not own the darkmatter CD. Feel free to use all other media provided with this release in your projects, Freeware or commercial.