Last time I counted, I owned over 500 books. The vast majority of those I've read more than once, although I do own a few that I have yet to read even once (War and Peace comes to mind...).
I almost always have more than one book on the go (and no, I don't have a problem keeping them straight). I have books in both bathrooms, beside my bed, and in the living room. If I know I'm going to be doing something that consists of a lot of waiting (airplane travel, doctor's offices, etc.), I try to remember to take a book.
If I forget? I'll read anything that's there. Books, magazines, advertisements - and yes, even those informational pamphlets in the doctor's office that have been there since 1986, and that no one else ever reads.
I even read instruction manuals.
And the worst thing about owning so many books? Moving.
What's your B?