Regarding ebooks, i don't have a Kindle (although i'm seriously tempted), what i like to do, is to buy the actual book, and then download the ebook copy (which i don't feel guilty about, since i already own the damn book). That way, i can read the physical book when i'm at home/at the park/on holiday, but i can also pick up from where i left off on my phone whenever i want, e.g. on the bus.
I wouldn't want to get rid of physical books completely, because i think they do have major benefits, but i also like the ability to carry around the book on my person at all times without having to widen my pockets.