I think this is a great question as Im forever wanting to make extruded like indents in surfaces, but the split poly's tool can be quite a long process. That booleans post with the cylinder 'stamping' the cylindrical shape into the cube looks like it could be the answer, but I have tried this on one of my models, and when i did an error message came up saying:must have exactly 2 polygons selected. ??? The way I used it was, im modelling a keyboard, and the cylinder/booleans thing I was going to use for the headphones socket. So the keyboard body itself has already had quite a bit of work, so the only difference between the example in the post and mine was that two basic primitives were used rather than a more complex model, but the body of my keyboard was just a cube to start, ive beveled in some areas and extruded a bit, but at heart its just a cube. IT looks great in the example so why wont it work for me do you think?