(This "review" stretches the purpose of this blog a bit, but it's a related topic.)
When I bought my Kindle, I didn't expect to use it for anything other than reading (duh) and possibly viewing a PDF of a crochet pattern now and then. But of course, Kindle* can do more.
There's the (somewhat limited) web browser. At this point, I haven't used that feature since the first week I got the device. (It could come in handy, someday, but at its current level of usability, it's really more for "emergencies". If you have access to a real computer or tablet, you'll want to use that instead.)
Then there's the ability of the Kindle to play mp3 files-- whether you want to listen to music while you read (no thanks, too distracting) or an audio book. Mp3 files eat up space on the Kindle pretty quickly and for that reason (and others) I prefer to use a good old-fashioned ;o) mp3-player for most of my listening. However, if you don't have an mp3-player or just don't want to lug around another gadget, hey, at least it's possible to use Kindle for music and audio books.
One feature that I have used more than I thought likely is text-to-speech. The text-to-speech function has been disabled on some books (thanks to certain publishers), but for those that allow it, you can sit back and listen to your book for a while-- very nice when you need to rest your eyes, turn off the light, walk from place to place, exercise, crochet, etc., but want to keep the story going. It's a computerized voice, so it's not nearly on the same level as a true audio book, where you have a recording of a real person reading with natural inflection and emotion. Still, the listenability is much better than you might imagine; clearly, this technology has made some significant strides in the past several years. (Search YouTube for examples, if you're interested.) Some books (or writing styles) seem to translate to "speech" better than others. You have the choice of a male or a female voice and three reading speeds, and of course you can plug in headphones / earbuds if you don't want to disturb those around you.
Another unexpected development in my Kindle usage has been my interest in some of the games available for play on the device. My favorites at the moment are Thread Words and Jigsaw Words (some of which is almost too easy for adults, but is still fun). There are a few other free word games-- Every Word, Every Word Crossings, Shuffled Row-- but there are also other types of games available for free-- Blackjack, Pixel Perfect Puzzles, Number Slide, Dots and Boxes, Minesweeper, Video Poker, etc. (And if you're willing to pay for a game, there are many to choose from starting at 99 cents each.) I'd forgotten how much I enjoy word games. The only downside is that now I'm addicted to Jigsaw Words, to the point that I'm not making any progress in my reading. (g) Well, I've nearly solved all those puzzles, so I'll be forced to go back to the book.
...So that's why I'm taking my time with my current read. Every time I should be reading a page or two, I'm playing Jigsaw Words instead. ;o)
*I'm writing about the WiFi Kindle 3. Some of this may not apply to other versions of the Kindle.