I triple-dog dare you to go into Barnes & Noble and not look at the Nook display. You won’t be able to do it. Though the device is all but sold out until early 2010, the monolithic in-store displays have fancy paper-cutouts in the shape of a Nook with features and specifications on them which I’m sure will be just fine wrapped and under the tree this Christmas, thank you very much.

The Nook (Technologizer’s great review here) is part of the latest gadget bubble to take hold of the elder and technorati set, the e-book reader. Like the Sony Reader and the Amazon Kindle before it, the Nook allows you to buy books from the Barnes & Nobel store, download them via 3g nearly instantly, and begin reading. The Nook brings not much to the discussion that the other two devices haven’t covered; E-Ink screen, fancy keyboard, books and newspapers. The killer features on the Nook that are supposed to wipe out the Sony and the Kindle are, well, two.

First, there’s a color screen. No, not the whole thing, just an awkward strip across the bottom which allows you to see small covers of your books, and converts to device navigation when you’re not browsing.

Second, you can lend books. This one might have been a game changer, as neither the Sony or the Kindle allow you to loan books to other device-weilding book mavens. A game-changer were it not for the fact that you can only loan a book once. Once. One time for that book, period. It’s a gift that’s only almost as good as not being able to loan books at all. With friends like these… yeesh.

I have the Kindle 2 — Amazon’s remix of their self-acclaimed hit e-book reader. I love it. For sitting down and reading a book with my feet up on the couch, with coffee, and maybe a cruller, it’s the perfect device. The screen is clear, and the fact that it’s not backlit means no eye-strain for long reads. It’s easy to navigate. It’s compact and terrific for vacations on which I’d usually lug along a bookbag. It’s the best way to read a newspaper, too. Seriously, dead-tree apologists haven’t spent enough time on the Kindle; it’s like having a newspaper that is clean, organized, and searchable, right there in your hands.

But, then, I love cross-word puzzles. The Kindle has a keyboard, so I assume I’ll just turn to the crossword and get solving, right? Nope. No dice. No crosswords on the Kindle. For that, you have to turn to something like the computer or the iPhone, which I happen to have in my pocket. OK, fine. No crosswords. How about books not in the Kindle fancy-format? You bet. PDF. Effective two weeks ago, Amazon announced that Kindle users can now drag PDFs to their Kindle 2′s when connected to their computers, or use their Kindle email address and have the documents processed and mailed for a fee.

Or, I could go back to my iPhone and read any damned thing I want right now, PDF or not. And this, right here, is why hardware e-book readers will be one of the shortest-lived gadgets in tech. They’re very cool, until you realize they’re never quite cool enough.

The Kindle epitomizes the paradox of the single function device: focus on one thing and do it exceptionally well, while your competitor focuses on nothing and delivers much with mediocrity. Turns out that in all but the most extreme cases, people want a device the does more, more often, and smaller. I can read my Kindle or my Nook books on my iPhone. I can read PDFs. I can edit documents and take pictures and send emails and play games that let me push people down stairs.

The hardware failings of the Kindle and this ilk come only when you have really discovered your delight in the device. You love reading so much on it, that you want to read more. You want to read email and webpages. But you can’t, not without suffering through the pain of lag in the E-Ink screen. You want speed, but you can’t have that either; the device was designed to do all the heavy lifting that comes with turning pages, for crying out loud. Anything more and you need a laptop.

Luckily, and where I happen to be quite bullish, is in the e-book as a technology and platform for further development. The best thing that could happen to reading books electronically would be for all these devices to fail in spite of themselves — in spite of the industry they’ve kindled. That may just mean that people have rediscovered their love of the written word beyond email and the web, and that they demand more of the tools that help them consume it.

For anyone looking for a recommendation before you head out shopping for that someone special, I’ll keep it simple. Buy a Kindle. It’s less stupid than the others. Then see if you remember how to read.