[gcheong]

It depends on how you read. I am often reading several books at any one time (obviously not simultaneously) so having the ability to read one book for a while and then effortlessly switch to another at any time/location is a big plus for me. Having had the kindle dx for a while now, I find it pretty much equivalent to reading a paper book and I don't miss the paper versions at all.

[jfornear]

I do the same. I read easier books that don't require in-depth understanding on the iPhone Kindle app, and I go ahead and buy books that I know I'm going to have to look back to again and again.