Do you have a Nook (or a Kindle?)

I was in Barnes & Noble today and saw the big display of cases. It is possible that I am more intrigued and excited by the adorable Lilly Pullitzer and Kate Spade Nook covers than by the product itself. The people at B&N are smart though--they are doing a demonstration day on October 7 so you can see how it works. I have no idea how the things works and what I would do with it and that's obviously obstacle number one to wanting to purchase it. Looking at the materials they were handing out briefly though it looks like you can share books with people and you can get newspaper subscriptions (no more smudged black hands on the metro from news paper ink?), and the price seems really reasonable. At $150 for the basic model, it's the same as an iPod. But how much are books? How many can I keep at a time? What else do I do with this thing? Are they really worth it? It sounds nice in theory, especially because I have a substantial commute to work (and this is a very commuter friendly product), but I could also see it becoming "just another thing I have to charge the battery in"/paper weight if I had one. Do you have a Nook? How do you use it? Is it worth the money?