We all thought stand-alone e-readers were going to get wiped out by the iPad, but they're still here -- and there are still a slew of reasons to recommend them. If you're a student, they make a vital addition to your campus survival kit. They can be pricey, and they won't eliminate your need for a laptop, but the initial cost leads to long term advantages. Hardware e-readers give you the ability to rent or borrow digital versions of your textbooks, and in cases where you have to buy an e-book, digital titles are usually cheaper than the hard copies. They're also more interactive, letting you highlight the study points, take notes and share them, and click hyperlinks to go deeper into a topic. Also, the convenience of reading everything on one lightweight device instead of lugging a backpack stuffed with books can't be ignored. Still, the e-textbook industry is young, and distribution remains shaky -- read our companion piece "Are Textbook Publishers Blowing It...," for more about the roadblocks facing e-texts on campuses. Here, we run through the most popular options. And you could easily just read books on your tablet, or even on a notebook PC using desktop readers like Nook Study, or a web-based reading app like Amazon's new HTML5-powered Kindle Cloud Reader app. For this reason, we've included a few non-e-ink options at the end.

Kindle Amazon's Kindle, still the market leader among e-readers, doesn't have the wide-ranging functionality of a tablet or a smartphone. But the e-ink device is exceedingly capable at one very important thing: getting out of the way while you devour a book. This makes it great for reading novels -- Amazon's library is deep enough to cover the bulk of your reading lists for literature and humanities courses. Classics from centuries past (War and Peace, Dracula) are also available for free. But Amazon has added e-textbooks to the mix, allowing you to buy textbooks through its Kindle storefront, or, alternatively, rent textbooks for 30 to 360 days. Fees are prorated, so you only pay for the amount of time you need. You can highlight and take notes, and your annotations will be accessible when you log in to Amazon even after the rental period ends. Taking notes is a chore on the Kindle's crappy keyboard, but any book you buy or rent can also be read through Amazon's bevy of Kindle apps for laptops, iOS, Android, Windows Phone 7 and Blackberry platforms, so you can type wherever it's most comfortable. If you need to read EPub files, you can do so on a Kindle, but the device doesn't support those formats by default. You'll have to use free software like Calibre to convert the files to the Kindle's native MOBI format. If you want a basic Kindle with a six-inch screen, you can get the ad-supported reader for $114. The full price is $140 for the Wi-Fi-only version, which is what we'd recommend. Refurbished Kindles are available for as little as $100 right now. If you need a bigger screen, the 9.7-inch Kindle DX is $380. Before you buy, note this: Rumors are swirling that Amazon will be releasing an updated Kindle in the coming months, and possibly even a full-blown tablet to compete with the iPad. Any such device would obviously have Kindle power features built in. Nothing official yet, though -- expect more details to emerge in September or October. Read our full review of the Kindle.

Nook The touchscreen Nook is the easiest of the e-ink devices to hold. It trumps the Kindle by eliminating the hardware keyboard and removing the bulky "chin," so it's more portable and more comfortable to use during longer reading sessions. Like the Kindle, Barnes & Noble's Nook is great for burning through novels and business books, and for most reading lists on subjects like history and political science. Copyright-expired classics and Project Gutenberg texts are available for free, and the Nook's superior support for library lending opens up further possibilities for getting your hands on assigned texts. Barnes & Noble's Nook store is deep, but if a professor sends around PDF or assigns a piece of reading only available as an EPub, you can use the Nook to read those, too -- though you may need some software, such as Adobe Digital Editions, to load it onto the reader. When it comes to plowing through lots of e-textbooks, the better solution may be to move off the device and get the Nook Study app for Mac or PC. Within the app, you can take notes and highlight as you go, organize your coursework, and you can try books for a week for free. So while the device itself is great for reading text, to take full advantage of everything the platform has to offer, including full e-textbook support, you'll need more than the basic reader. The six-inch black and white Nook, which we'd recommend, is $140, and seven-inch Nook Color is $250. Barnes & Noble also sells refurbished Nooks at a discount. Read our full review of the Nook.

Kobo Touch Kobo is a dark horse in the e-ink market, but it's gaining some popularity, and the bookstore that feeds it is growing. The device itself is smaller and lighter than the Kindle, and much like the similar-sized Nook, it uses a touchscreen instead of a hardware keyboard. One of Kobo's advantages is the social gaming aspect built into the reading experience. The Reading Life software on the device provides you with stats about your pace and progress while you're working your way through each book, and awards you badges when you reach milestones or when you increase your reading speed. It sounds corny, but videogame-style achievement-unlocking rewards are an excellent motivator if you're a slow reader -- or if you're having a hard time tearing yourself away from reruns of Whiz Kids. The drag about Kobo is the lack of a robust e-textbook ecosystem like Amazon's or Barnes & Noble's. But like the other devices, novels are available in abundance, older texts can be read on the Kobo (and its apps) for free, and PDFs and EPub files can be side-loaded with minimal hassle. The Kobo E-Reader Touch Edition with Wi-Fi capability is $130. Stay away from the older version without the touchscreen. Read our full review of the Kobo Touch.

Apple iPad 2 The iPad's software platform trumps all the dedicated e-readers when it comes to breadth of utility. There are free reader apps from all the major stores -- Amazon's Kindle app, Barnes & Noble's Nook app, Kobo Books' app -- as well as apps like Stanza, Bookworm and Good Reader for loading up on EPubs and PDFs. And of course, Apple's own play, iBooks, comes pre-installed. There are dedicated iPad apps for e-textbook services like CourseSmart, Vitalsource Bookshelf and Kno that let you read and take notes. Instapaper ($5) can handle all your assigned web-based articles. The touchscreen is pleasant enough for taking notes, and you can access all stripes of online educational collaboration services either through an app or through the full-blown browser. Given its versatility, it's kind of a shame the iPad doesn't make the most pleasant reading device. The current iPad is 1.33 pounds -- more than twice as heavy as a 8.5-ounce Kindle -- and its 9.7-inch screen is backlit. Fatigue creeps in to both the eyes and the arms after only a couple of hours. The battery gives you about eight hours of study time -- no match for the e-ink devices, which can last days from one charge. Also, compared to e-ink readers, you'll pay out the nose. Wi-Fi-only iPad 2s start at $500, and that should be enough for almost everyone. Add Verizon or AT&T connectivity (which is probably unnecessary on campus) and you'll pay as much as $830. But of course, you really do get much, much more than an e-reader for your money. Read our full review of the iPad 2.

Android Tablets Like the iPad, you can load up your Android tablet with a wealth of free e-reader apps. Kindle, Nook, Kobo, Google Books and CourseSmart are just some of the apps available for Android tablets. And yet, Android tablets suffer from the same usability problems as the iPad -- the backlit screen, the bulk, and battery life aren't as friendly to all-nighters as dedicated e-ink devices. But the beauty of Android is the wide range of hardware choices. Need a bigger screen? Get a Motorola Xoom or a Lenovo IdeaPad K1. Want something compact that's easier to hold? Get the seven-inch version of the Galaxy Tab. In fact, if portability's your biggest concern, Samsung's 7-inch tablet may be the best Android-based e-reader. The screen, a standard LCD, is not as bright and as clear as the iPad's beauty, nor as infinitely readable as an e-ink device. But the tiny tablet is remarkably easy to hold with one hand. It really feels like a jumbo-sized cellphone and slips easily into any bag and many jacket pockets. The downside? It's old -- performance is sluggish, thanks to a 2010-era processor, and it runs Android 2.2 Froyo. But rumor has it we should expect an updated version of the Galaxy Tab 7 soon. So if you want to get small for fall, drop $350 now for a Wi-Fi only model. Otherwise, play the waiting game, or go for a bigger option. T-Mobile's G-Slate has an 8.9-inch screen and weighs 1.37 pounds, so it's not as portable but still relatively svelte. It has T-Mobile service built in, so it's more expensive and requires a data contract. The G-Slate starts at $530 and goes up from there. One of the lightest tablets is the Galaxy Tab 10.1, and it's our recommended choice if you want a big, crisp screen. The 16GB Wi-Fi only version, running Android 3.1 Honeycomb, is $500. There's a Samsung 8.9-incher coming, too, though it's not on the market yet.