I bought a box of old cylinder locks from ebay. There is one of them that I cannot pick. When I lift the first pin, the lock rotates 5 degrees. When I don't lift the first pin, none of the other pins bind. I shimmed the thing and took it apart. The back five pins were really low - so low that they just barely passed above the shearline. The top part of the cylinder is a bit worn down so that it is possible to rotate the plug a bit (but not far) when these pin stacks are not raised.
I think that this concept could be exploited to create a lock that is difficult to pick. The first pin is normal, the other pins are as shown in the picture below. The concept is a bit similar to spool pins I suppose, except that spool pins are easy for me whereas this lock seems to be beyond my abilities. There is no counter-rotation as there is with spool pins. The diagram below represents the cross section of this old lock of mine, except that my lock rotates much farther than the one I have illustrated below.