Thanks for these utilities! There seems to be an overt emphasis on Windows for conversion utilities, with Linux and Mac sitting, dejected on the sidelines.
I hope to give these a run on Mac OS X, and if it works you can add that to the subject. Bash comes standard, and Fink (Mac OS X port of debian's apt) has xpdf and ghostscript, so those are easy.
I don't have my PRS500 yet, so it'll be a few days before I can test.