I have a Kindle 3 and find it very useful, especially when travelling. It can apparently store up to 3000 books. A feature I like is that you can upload your own documents which I find useful for meetings. The screen is very clear and readable but only in greyscale. I have the 3G one and it also doubles up nicely for reading web-based emails. You can surf on the web with that version but the screen size and lack of colour means that it works best for text-based pages (e.g. Mudcat and other forums).

While it's a very nice, well-designed and handy gizmo it still doesn't really replace having a book in your hands.