S...
     I want to convert a pcb layout file which is in gerber format
     to PostScript to print on paper....
     S...

     See http://WWW.ECAM.com/    Excellent gerber viewer/editor/printer
     They have a 7 day timed demo, and untimed (limited) demo.
     (It also scales with independant X and Y factors to help compensate for the
     paper stretch.)
     Joe