There's also Calibre. It's available for Win/Osx/Lin. It's an ebook librarian program, but does have a viewer and format conversion. I use it under Ubuntu Linux interfacing with a kindle and converting other formats to mobi for the kindle (varying degrees of success - not so good with scanned image pdf input, but good for most other formats). You can also use the viewer to create a normal pdf you can read on the computer with any pdf reader.

Mick