I've always been a holdout against ebooks. Reading a large amount of text on a computer screen is not appealing, and even a laptop is just not portable enough. It's heavy, you can run down the battery way too soon for a good reading experience if you're not plugged in, etc. PDAs and cellphones are obviously a lot more portable, but really, that's a tiny screen.
As for dedicated ebook readers... One is from Sony. After the rootkit nonsense of a few years ago, I'll never trust a Sony device again. Some of my friends have Kindles, and they love them. I've looked at them, held them--and not loved them. Not hated--just, not loved them. I suspect that if I traveled a lot, and carrying enough reading material on planes and trains were therefore an issue for me, I'd probably have succumbed. But I don't, so I didn't.
Then this summer my mother decided she wanted an ebook reader, or was convinced by my sister that she did, so that she could check books out of the library without having to leave her apartment on the days when she's less than fully mobile. She wanted to go look at ereaders, and asked me to come with her. We wound up at Barnes and Noble, looking at the Nook. Excuse me, the nook. B&N favors the lower-case n for the name of their device.
What can I say? I fell in love. It's the right size. The display is nice, e-ink really is almost like reading a printed page, far better than a typical computer screen display. It's about the weight of a trade paperback, and a bit smaller in dimensions--even with the optional but highly recommended case/cover. The battery life is more than decent, in part because the nook uses power only when changing something (such as turning a page), the touchscreen portion is active, or you're using the wi-fi or 3G capabilities. About once a week, I need to plug it in for a few hours, and the rest of the time, I don't have to worry about it at all.
It's easy to adjust the size of the text to what's comfortable for you, and I do find that on the nook screen I prefer a larger text size than I would like on the printed page. I've also loaded on a few pictures of my dog to serve as my screensaver; it's easy to do, and fun to see her cute face every time I pick it up. Once you've got the book you're reading open, and the control touchscreen at the bottom goes dark, you can turn pages by swiping a finger over the darkened touchscreen. It's about as close to reading a print book as an electronic device can probably achieve.
Of course, if you spend the money on a ebook device, you're not only concerned about ease of use. You're also concerned about availability of material. Overall, ebook prices are closer to paperback prices than to hardcover prices, but that's not universally true. The sad truth is that many publishers are so afraid of piracy that they make ebooks expensive and load them down with DRM (digital rights management) that makes them hard to use conveniently--and of course impossible to lend.
However, I'm finding more than enough that's available at close-to-paperback cost that I don't feel unduly restricted in my reading choices. Barnes & Noble also offers some free ebooks; so does Amazon for the Kindle. B&N, unlike Amazon, does allow "lending" of ebooks bought from them--if the publisher agrees. It's very restricted (only for two weeks, and any given book can only be lent once), but it's a beginning. When the publishers realize that this is not hurting but rather helping their sales, I'm sure it will expand.
You can borrow ebooks from your public library, too (remember, this is where we started, with my mother's desire to do so.) What and how much is available this way will depend on what library or libraries you belong to, and what consortia they belong to, but if you are open in your reading choices, you may find that there's plenty of reading material available.
There are also other sources of free ebooks. At Manybooks.net, there are many older classics and older forgotten-but-excellent books available, out of copyright protection and unburdened by DRM. Some authors offer some of their own books as free or inexpensive ebooks, and some publishers, in contrast to the publishers who are terrified of the digital age, do the same with older titles. If you are a science fiction reader Baen Books is an excellent source of free sf, and you should also check out their ebook store for more current titles, not free of course, but not expensive if they're the books you want.
I'm enjoying my nook, and I think I will continue to do so.
Oh, and my mother? She wound up buying a netbook, instead, which makes sense for her needs. She had no computer at all, and library ebooks need to be downloaded to your computer first and then transferred to your ereader device, so the nook, or the Kindle, or the Sony reader, alone, wouldn't have helped her. She also wanted email access. Her netbook isn't much bigger than the nook, and it does the other things she needs. Less battery life, of course, but since the whole point is that she wanted something that would allow her to not go out when she wasn't feeling up to it, that's not really a issue. She can curl up and read with this, and still keep it plugged in most of the time.
Do I think ebooks are going to replace print books? Not anytime soon, no. They're a nice additional option, though.