mpage is a wonderful little utility. It will convert ASCII text into postscript in a variety of ways. One of the most useful of which is the ability to put more than one page of normal text onto a single side of a printed piece of paper. Using mpage to put multiple pages of code onto a single side of a page makes code easier to trace and saves a lot of paper.
mpage -2 main.c | lpr -P ps3457
Will print four pages of code onto a single sheet of paper (two pages per side). You can also just create a postscript file:
mpage -2 main.cmain.ps
mpage can also be used for postprocessing existing postscript. Say you have a large file of transparencies or slides that you've created and would like to print. If you just want to use the printout as a reference, you probably don't want twenty huge printouts of your twenty big slides. You can
mpage -4 presentation.ps | lpr -P ps3457
To put four slides on a single side of a sheet of paper.
If you familiarize yourself with mpage's options, you'll probably find a lot more uses. See the man page for the plethora of options.