I just got a Kindle for my birthday, and I love it!
The main reasons why I chose the Kindle over others:
1) the display is as close to reading the paper version as it gets ... I did not want a reader with a backlight as it is much harder on your eyes.
2) it has a keyboard, which makes searching and other tasks much easier (I'm not a huge fan of the touch screen, but that's probably because I just don't have a lot of experience with it).
3) price (now only $189!).
4) when you purchase e-books for your Kindle through Amazon, they are automatically archived on the Amazon website. This means that if something happens to your computer or your Kindle, you won't have lost all of the e-books you have purchased ... you can re-download them for free! It also means that if you run out of space to add more content to your Kindle, you can choose what items you want on your Kindle at the moment and leave other items off without actually losing them ... they'll stay in your archive on the Amazon website.
While different companies (eg. Amazon, Barnes & Noble, etc) each have their own readers and sell e-books on their websites that are designed to work with their reader and not others, their are lots of other places to buy e-books as well! I think pretty much all of the readers now support many file types, probably the most common of which is PDF. Sites such as
this one, for example, sell a huge variety of books in PDF format. This means you can use them on any reader!
If you download knitting patterns from sites such as Ravelry, then you could load them right on to your Kindle (or other reader) to take with you. I'm looking forward to being able to do this ... I'm forever printing out new copies of patterns as they tend to get chewed up looking (I take my knitting with me a lot and the print out of my pattern seems to always end up in the bottom of my bag!).
I only wish I had had one of these when I was still in college ... it would have saved me a huge amount of space and money on textbooks!