PDFMunge: Improve the Legibility of PDFs on e-book Readers
This little script performs some processing on PDFs in order to make them easier to view on e-book readers. The primary functions are stripping away large margins, creating an imitation of landscape mode on devices that don't support it by cutting each page in half, and rotating everything 90 degrees counter-clockwise. It can also remove individual pages from the file.
Basically, it turns this: