Enscript is pretty cool program; Not only it can prettyprint source codes in many languages (and offer extension capability at various levels), it can also generate HTML prettyprints in addition to PostScript, which makes it a choice if you want to webify source code.
Enscript was written by Markku Rossi (yes, yet another quality software package from Finland =).
Funny Factoid: Enscript man page includes example enscript -Possu foo.txt for printing foo.txt to printer "ossu". It might be worth mentioning that "Possu" is Finnish computer jargon for "PostScript" (and, incidentally, also means "pig").