There is software that will convert books in between various ebook types.

I like the kindle better than the nook.

If you buy the 3g version of the kindle, you have web access around the world free. So now when I travel, instead of carrying a couple guide books, a couple of books to read on the plane, a stack of PDFs for work, possibly a netbook to get on the internet in hotels, and looking for internet cafes or free internet... Now I can just carry my kindle - that makes my carryon luggage and the crap I'm carrying around like 10 pounds lighter easily (it's probably more than that). Yes, websurfing through the kindle on 3g isn't all that fast, but it works pretty well with facebook, wikipedia, the weather channel and yahoo mobile. So I can log on, tell my family I'm okay and give 'em small updates from different countries for free. I also have 800 or more books in my kindle with a 2 week battery life (you do use it faster if you web surf on it). I can read pdfs on the kindle on an e-ink screen much easier than I can on a backlit screen - you can use it outdoors without having to worry about sunglare.

I like books, but i hate storing them and I hate moving with boxes of books. The kindle where all the books i have are stored in my online amazon account and I can just redownload them if I lose them or something happens to them is great.

I take my kindle with me kayak, bike, and backpacking on long camping trips. There are times when I'm on remote islands that I can't get a reliable cell phone signal to call out to tell my mom not to worry, that I can get on the kindle and just post to facebook to tell my siblings to call her. I keep all the nautical maps of the areas I kayak on my kindle - so if I lose my maps, go off the charts I'm on, or something happens to my gps - I can figure out where I am.

I recently went on a cruise from LA to florida via the panama canal - as long as I was relatively near land, I could get a 3g connection on my kindle (I ended up having to deal with the editor for a paper I was having published via email - and it was something like $75 for an hour of internet access via the cruise ship).

the nook doesn't come with free 3g - I think the touch screen & the color screen is gimicky, but that's all depending on what people want to use their ereader for.

Mine just pretty much goes with me everywhere and anytime I need to wait, I can pop it out and read on it. For what it's worth - No, I don't have a fancy cell phone that I can get emails and websurf on it or pay for a data plan (mostly because of the activities I do, I need a phone that works really well as a phone and is rugged enough for me to rely on) and I don't pay for international charges on my cell phone. Those of you with fancy cell phones and data plans won't be as amazed at the free internet aspect of the kindle as I am.