E-Readers are picking up steam like never before, and its no wonder. They allow users to choose from millions of books, magazines and newspapers, all of which display on a small gadget with lots of memory. This eliminates the hassles that come with carrying and holding heavy books, messy newspapers and glossy magazines that can be difficult to read in direct lighting.Despite all the conveniences that E-Readers can provide, many of the 30+ new models that have entered the market in 2009 and 2010 can have some downsides that make them difficult for seniors with certain limitations to use. So before you jump on the eBook bandwagon, make sure you know where to invest your dollars based on your needs.What Seniors Should Look for in an E-ReaderLightweight DesignE-Readers are all about convenience and portability, which means they should be significantly lighter than their hardback or even paperback counterparts. Ideally, they should weigh less than 12 ounces.COOL-ER ClassicThe COOL-ER is one of the lightest E-Readers on the market today, weighing only 6.3 ounces.Large ScreenJust because the E-Reader weighs less than an actual book doesnt mean it should be smaller, and therefore harder to read. Screens on E-Readers should be at least eight inches for those with poor eyesight, though 9.5 inches would be better.SkiffThe Skiff has one of the largest E-Reader display screens, at 11.5 inches. While this may limit the devices portability, it is also extremely thin, at only .26 inches wide, and flexible because its made from rugged metal foil e-paper.Large On-Screen IconsThe relatively large sizes of E-Reader screens mean that icons appear larger as well, making it easier for seniors to navigate through the menus. Depending on the screen size, anywhere from four to nine icons should display at one time. An E-Reader with an eight-inch screen can display nine large, well-spaced icons easily, while a six-inch screen should handle six or seven just fine. Any more, and the device can look cluttered with tiny, indistinguishable icons for those with poor eyesight.Sony Reader Touch Edition PRS-600Sonys icons are large and feature a minimalist design, making them easy to see and identify. The main menu on the six-inch screen contains only seven options, with corresponding pictures that are easy to memorize once youve used the device a few times.High ResolutionA larger screen and text doesnt necessarily translate into easy reading if the resolution is low. Chunky, semi-blurry text can cause headaches, eye strain and readers fatigue. So purchase an E-Reader with a high resolution. If your screen is nine or 10 inches, be sure your resolution is at least 1200 by 824, if not 1280 by 1024.iRex Digital ReaderThe iRex has a 10.2-inch screen and a 1280 by 1024 resolution, making it ideal for people who like to analyze detailed documents that feature photos, graphics and other visual aids.Shatter-Proof ScreenMany people store their E-Readers in suitcases, laptop bags, backpacks and purses where they will bounce around with wallets, medication, cell phones, keys and other must-have items. While E-Reader protective cases are available, they cant protect the devices from all accidents. They also cant protect E-Readers from their owners, who may drop or smack the E-Reader against other objects due to arthritis, weakened muscles or poor eyesight while navigating around the house. This is why a shatter-proof screen is so important. It wont typically stand up to being stepped on, but it should protect this pricey device from the whacks, smacks and general abuse that we put most of our baggage through.Plastic Logic QueThe Que first premiered at CES this January and will hit shelves this summer. The device touts many features that make it a great E-Reader, but the best one might be the shatter-proof plastic its made out of. Hey, these E-Readers are expensive and very thin, which can be a dangerous combination when theyre in transit. This shatter-proof material gives you a little more assurance that the device will come out of your purse looking just as it did when it went in.NookBarnes & Nobles nook has a six-inch screen, which means it may need additional help to make its smaller size compatible with avid senior readers. One way it does this is by employing E Inks Vizplex film, which makes the small screen easier on the eyes. Many E-Readers have caught onto this films readability, and Vizplex seems like its just a few steps away from becoming the industry standard.Touch Screen TechnologyTouch screens are key features for seniors who have trouble operating small buttons with even smaller text. They also make great substitutes for the pens and highlighters that many readers traditionally use on their books. A touch screen will allow you to highlight passages or make notes in the margin. Some E-Readers come with keyboards that can perform similar tasks, but its much more difficult than touching a stylus pen to a screen. The same is true when navigating through menu options. Who wants to press a bunch of buttons or move a cursor across a screen when you can simply point to what you want?iRex iLiadHighlight, notate, draw and doodle with the iLiad. Its stylus pen lets you do it all. You can also send your annotated works to others who can read, edit or add onto them. An added benefit of the stylus is that you can download Sudoku and crossword puzzles onto your iLiad. Complete them in one sitting or send them to your grandchildren to see if they can fill in the blanks youre stuck on.Audio CapabilitiesSeniors who have trouble reading due to failing eyesight should purchase an E-Reader with audiobook or text-to-speech capabilities. These devices are convenient for seniors who only need a little assistance when prolonged reading periods become too laborious. If you have a habit of reading in short spurts because your eyes cant take the strain, then this audiobook feature is for you. If you rely almost 100 percent on MP3 players or books on tape to do the reading for you, then E-Readers are an expensive, needless substitute to these devices.Kindle 2Few E-Readers have ventured into the Read-to-Me territory. The brand that seems to do it most successfully is Kindle. This feature is available on the Kindle 2 and Kindle DX, both of which read text in a monotone but understandable voice. Text-to-voice is available on many books, but not all of them. We suspect that this will be a key feature to watch in the upcoming years as it becomes more sophisticated and widely available. But for now, these two Kindles are your best bets.