Quote: "If you want a .X world, you got to have the enhanced version and use memblocks, which are pretty hard to learn."
I hope you have if you want to use memblocks...
Quote: "do you know how to do memblocks? if so,what are they? and how would you use the .x model as a terrain?"
I happen to know how to use memblocks yes.
And using .X files as a terrain means that you create the terrain like any other object file in milkshape, anim8or, etc. These can be constructed by memblocks too BTW, but It'll be much easier just loading them.