OK, so I've had a Sony PRS-505 Reader for a little over a year, and I really like it. With this little device, I can carry around a full library with hundreds of books -- and it only weighs as much as a typical paperback.
I've been able to read (and re-read) tons of classic works (Arthur Conan Doyle, Shakespeare, Poe, Darwin, Wilde, etc), along with plenty of new books. I've read Terry Brooks, Matt Ridley, John Scalzi, and many other new authors releases. And the best part is -- none of the "ebooks" is more expensive than a regular paper book, and most often they're cheaper by 15-50%.
While there are some features that the Sony reader doesn't have (wifi access, touchscreen, larger screen size, etc), all in all it is a fantastic little device. I've had tons of people ask me about it when they see me reading, and I've probably been an unpaid salesman for the thing -- I know of at least three people who've bought one because of my recommendation and demonstrations.
One of the best things on the reader is it's ability to reflow PDF files, so I can easily read a scientific journal paper (two column) without having to actually print it out. And in low light or when I'm really tired, I can increase the font size.
If anyone has questions or wants to see one of these amazing gadgets in person, just let me know. I hardly ever buy a paper book anymore (unless the author is a Luddite who refuses to allow their books onto electronic media -- there are a few).