All the time!! I love reading and will just grab one of my books and start reading--I usually end up with up to three going at the same time and yes, I do keep them straight!! Don't know how--can't keep anything else straight, lol!!
I always do. I'm almost always in the middle of one Harry Potter book, one non-fiction book, and one fiction novel. I like to mix it up. Somedays I just want to read a novel, others I want a nonfiction.