If anyone is interested, I recently played around with creating a pdf of a free ebook (like from Gutenburg) for my Kindle and was very happy with the results. I tried using Word and printing to CutePDF, but that did not work because it did not keep the page size I had set - it used the 8.5 x 11 letter size, and had the words in the middle of each page. I searched online and found that OpenOffice, which is basically the Linux version of Word and is free to download, will let you export to PDF and will keep the page size you set.
So for the the 6" kindle screen, I set the page size to 3.5 by 4.75, with a margin of .25 all around. I like the Book Antiqua font, and I used font size 11, but I think a size 10 or 10.5 might be better. Originally I had page numbers in a footer, but found it wasn't necessary as the Kindle displays the pdf's page number in their progress bar.
Here is a pic of what it looks like, and it might be too small and fuzzy to see but the book came to 622 pages. A smaller font would, of course, make this less.