I've been learning a lot about the Kindle since my girlfriend got me one for Christmas.
At first I wasn't too excited about it. I like regular books. No big deal if they get lost, wet, or ruined. When you're done with one, you can give it to someone else. And you can generally find used books pretty dang cheap, or check them out at the library. On the other hand, it did appeal to the environmentalist in me -- no wasted paper. And books can be heavy and bulky when you move.
I started to get pretty excited about the Kindle though when I found out that it could browse the Web via the 3G network. Not only that, but the browsing is actually free! At least its free for now, I read rumors that Amazon may change that later. They say that the simple browser is meant for sites that are mainly text, such as Wikipedia. That's fine with me. And I did get my GMail to open on it.
Then I started to lose my enthusiasm for the Kindle when I learned that it doesn't support the EPUB format, which apparently is the prevailing standard for e-books. That's what Sony uses for their reader and that's what Google is using in their massive Google Books project. So Sony and Google teamed up to offer an open-source approach to e-books, and Amazon represents the leading giant with the closed proprietary format.
But my latest swing is back to enthusiastic for the Kindle because of the wonderful volunteers converting books from the EPUB format to the Kindle format(s). That combined with the fact that book copyrights usually expire 70 years after the author's death means that there are LOTS of public domain books that were converted from EPUB format to a format for the Kindle and are available to download for free on the Kindle! So I can have a library of classics all stored in my small Kindle at all times. If you like classics, then that's exciting! I downloaded seventeen free books yesterday, including a few from a couple of my favorite old authors, H.G. Wells and Jules Verne.
Add in lots of little neat features like built-in dictionary, ability to search books, and being able to see all your bookmarks and highlights in one list, and it really is a fun new way to read.