One of my favorite Kindle features is "sample this book." For no charge, you can download the table of contents and the first chapter or two of any Kindle book and decide at your leisure if you want to buy the book and read further.
Now you don't even need a Kindle or other e-book reader to sample books in this way. You just need a PC (no Mac version yet, but Amazon promises it is on the way) and Amazon's free sofware.
In addition to providing sample chapters of the 376,000 books available in Kindle format, Kindle for PC displays color. Lack of color for most books is no big deal, but graphic novels, childrens' books, and maps need color.
Steve has recently started learning to play guitar, so we're going to try downloading music books (at the lower Kindle price). Music books would be much too small to read on a Kindle, but I think they'll look fine on a monitor.
Of course, I don't intend to start reading all my books on a PC now, but it does provide one more option. Try it out!