I wouldn't have thought that I'd have a big need for reading PDF files on my Kindle, but I've already had a need for it several times - reading drafts of my work-in-progress (WIP) and previewing PDF files of book entries for The Global E-Book Awards that I'm judging.
So, I searched out a solution, and found one. Eureka! I'm sure I'm not the only Kindle owner with a need for this, so I'm posting what I found. There's information on Squidoo giving some great tips and information. In this article, it refers to a FREE software called Calibre, and that's the one I tried. And it works like a charm. I converted two PDF books into MOBI format and emailed them to my Kindle. Now they are readable. Love it! Now I can read these books that I'm slated to judge while I'm working-out at the gym, and I won't be confined to reading the files on my computer.