Rotate only an extrusion On this site:
http://blenderartists.org/forum/showthread.php?283909-ramp-modeling

Poster Kaluura gave an excellent demo of ramp building.  I've done a lot of complex shapes but I couldn't get the ramp to work and make the edges meet other objects in my scene properly.  This demo looks like it will do the trick and I understand most of the steps.  I'm actually stuck near the beginning however, because in step 2, he has a nice graphic and says "Extrude without moving. Rotate the extruded loopcut on the Z axis around the 3D cursor."

I can't seem to rotate the extruded face while leaving the original face in place.  Can someone more experienced and wiser translate this step for me?   Thanks.
You notice his cursor is offset to the left so when he rotates the face, it rotates around the cursor position instead of in-place.  To get that effect you need to make sure you are using 3D Cursor as your pivot point before rotating the face.  The button for pivot point is at the bottom of the 3D view next to the viewport shading button.