I've noticed that my book buying habits have changed since getting my Sony 505.
I'm much more concerned with price now than I think I was before (maybe because its so much easier to spend money when I can instantaneously download content, right from my bed
).
So I've moved away from books that I don't think are worth the money, putting them in my queue for a time when they'll go on sale or when I've built up enough FW Micropay to buy them.
I put really easy, pulpy reads into this category (like Jonathan Kellerman, Star Trek series books, Dean Koontz, and the like), and wait for them to be sub-$5. In the past, I would have forked over the $6.99 or $7.99 at the brick and mortar bookstore to get them.
Do you think that your spending habits have changed, because ebooks are so easy to get?