As we've mentioned before, Laura and the kids brought Kindles on our trip, and they love them. With lots of time on buses and hanging out in hostels, the kids have been able to keep up with their favorite adventure and fantasy book series and play Scrabble, and Laura likes to read the New York Times occasionally to keep up with news from the US. They work flawlessly and as an engineer I appreciate their elegant design.
I bought a Nook over a year ago, and while I enjoyed using it in the U.S., I've discovered that I can't buy new books or newspapers from here in Chile. Barnes and Noble apparently is looking at my IP address (the internet address assigned to my Nook when I sign on to a wifi network here), recognising it as assigned to an internet service provider that's not in the U.S., and not allowing me to buy anything. Here's their official explanation.
Yes, I can get around this silly restriction (that's a topic for another post), but it's a pain. Also, having now spent some time with the Kindle, I'm realizing that the Kindle is a far better machine. The Nook is too heavy to comfortably hold in one hand, the buttons are poorly placed, and the screen is too shiny, so it's uncomfortable to read via a book light at night, or in sunlight. The main advantage of Nook is that you can get books from places other than just BN, like Google Books, but I haven't felt the need.
So, if you're planning on travelling, or even if you're not, go with a Kindle!