FYI Amazon's working on a thinner, faster Kindle that should come out before the end of the year. I've got a K2 but I've never tried the Nook, so can't compare.
I really like the Sony Touch. I also like that I can read PDFs and documents from my computer. Saves me from wasting paper and ink on printing out long newsletters. I got several ebooks for free from Smashwords and you can also borrow them from your local library but I haven't tried that yet. I like how it is easy to change the font size and flip between books, and the machine keeps the page you were on.
My sister has an iPad (they're heavier than I'd figured) and she always uses it flat on the table. I think the Kindle or another dedicated ereader would be much easier to curl up with in bed or a comfy chair.
The iPad's very comfortable to use, and works perfectly either in landscape or portrait mode. Get a good case for it and you can prop it up at a variety of angles, even in bed. What's nice about it as a bedside device is that the ereader's backlit, so you can read with the lights out--thus not disturbing your spouse. Love the iPad!
Well I'm gonna be bias because I have a Sony Reader and I loooooooveeeeee it! I never wanted a Kindle because I wanted to be able to get books from places more than just Amazon. Also, I didn't like the stuff I heard about Amazon's practices with the Kindle. I also didn't like it that Amazon has the power to go into your Kindle and erase books even if they made a boo boo. No way. I think Amazon has enough power as it is, LOL!
I love the Sony Reader. I received the PRS-300 for Christmas and I plan to upgrade to the latest one when possible because I heard you can edit things on it and I think it would be good for me to work on my manuscripts with.
What I love the most about having an ereader is that you can read your WIP's on it and it looks like a real book! It gives you the feel of how your work would look and it helps the editing process.
An article in the NY Times business section, yesterday or the day before, predicted that twelve months from now there will be $100 e-readers that people actually want to buy. I plan to wait and see if that's true.
I love my iPod Touch because it's small enough to carry with me everywhere, and I can get apps to read pretty much every format except Sony. (And I don't think Sony has any exclusive material, that I know of.)
Well, except for the irony of Apple's own iBookstore. That will be available for the Touch very soon - but I don't know if older versions of the Touch can run the latest OS that's necessary to use it. So you'd have to buy a new one to be sure. The lower end is $199. That's 8 gigs, which is plenty for books, but can fill up fast with video and music.