12/12   In emacs, is there a way to delete 10 least visited files
        in the buffer?
        \_ Maybe this: Do C-x C-b to get the buffer list, then move the cursor
           to each of the bottom 10 lines and press 'd', then press 'x'.  It
           looks like the files in the buffer list are sorted by time of last
           usage.
           \_ problem is C-x C-b TAB shows alphabetized list...
              \_ What version of emacs are you using?  The one on soda is
                 21.1.4.  There is no C-x C-b TAB, and C-x C-b does display the
                 files in last usage order.
              \_ I use Emacs 22.0.50.1 (i386-apple-darwin8.7.1) on OS X and it
                 sorts by order visited.  I suspect the ordering of the buffer
                 list is tunable in your .emacs -dans
        \- note: if you use frames, this may not work as you expect.
           also i think buffer-menu.el was re-written around for some e22.
           you can look at the Buffer-menu-sort* functions for display order.
           also see midnight-mode and clean-buffer-list.