C-u M-x ps-print-buffer-with-facesThat prompts you for a .ps file name, which you can then use ps2pdf on and open with Preview.app.
Setup can be done in .emacs -- for example, to get two-column printing:
(setq ps-paper-type 'letter ps-font-size 8.0 ps-print-header nil ps-landscape-mode t ps-number-of-columns 2)and re-evaluate the .emacs buffer with M-x eval-buffer if you don't want to restart emacs.
More documentation can be found in the ps-print.el file, which is deeply buried where you can't find it with Spotlight:
/Applications/Emacs.app/Contents/Resources/lisp/ps-print.el.gzand also: http://www.gnu.org/software/emacs/manual/html_node/emacs/PostScript.html