In a fit of extravagance, I bought a Sony Reader. I must admit that the ad about never again finishing your last book while on the plane half way to California got me. I'm intending to use it for traveling and carry it around for unexpected waiting time; I haven't actually sat down to read a book on it yet.
But some first impressions. The easiest thing to do with it is to buy books from the Sony Connect Store . They have over 12,000 titles, which if you aren't into bestsellers isn't really very many. But certainly I can find books there for traveling, when I like to hide in a mystery anyway. Those books are easy to read, with three choices of type size, though I hear illustrations aren't always good.
The next easiest option is Manybooks, which has taken books from Project Gutenberg and formatted them for Sony and made them available for free. They say they have over 16,000 books. Silk Pagoda has 10,000 books on a DVD for $24.71 (free shipping) formatted for Sony. Other Project Gutenberg books can be read on the reader, but in PDF form the type is much too small for my old eyes. It is a little better in landscape mode, but still hard to read. There are several programs available to translate PDFs and documents into more readable form, but I tried two and couldn't get either to work. MobileRead Network is the place to find geeks discussing these. I tried downloading a Project Gutenberg book as plain text, and the text size shows up fine (and adjustable) on the reader, but with very irregular line lengths (the plain text file had hard line breaks for lines longer than the reader accomodated, even in landscape mode).
Note: a later post has solutions to some of these problems.