I use my phone as an ebook reader (using Aldiko), and I noticed that, since I started using ebooks, I'm reading significantly more books then before. Especially in bed.
I find it a lot nicer to read this way, lying on my side, than before with hardcopy books.
It's a lot less cumbersome, you can just hold the phone in one hand, with the lights out, flip the pages with the volume key.