"Do you read only one book at a time, or do you have several going at once?"
Personally, I really can't "read" two books at once. I usually have one that I focus on and will occasionally have a "back-up" book around if my mood changes or if I left my main one somewhere out of reach. The second one is usually a re-read, though, so I almost never count is as reading more than one at a time.
I'm currently reading Delirium, by Lauren Oliver, and while I'm loving the idea of it, it's hard to read another dystopian novel. This one is good, but so many before have also been good. Why are dystopias so draining on the soul?