I am currently reading The Host by Stephanie Meyer (DD said I must read).
I just finished The Geography of Bliss by Eric Weiner which was an interesting look at how people define happiness and what makes us happy and Ultramarathon Man by Dean Karnazes which is very motivating even if I am only running 6-8 miles instead of 100 or more at a time.
I've been on a Flannery O'Connor kick for the last month or so. I'm currently reading "Wise Blood". Before that was "The Habit of Being" (a collection of her personal letters) and the complete collection of her short stories. Next I'll read "The Violent Bear it Away". *
Her work is pretty dark for the most part, although there is humor subtly hidden away in it (you have to be a little wierd to find it, but that's me). Anyway--I'm not sure I'd recommend her for a light summer read.
A fun series of books on the lighter side is written by Alexander McCall Smith, about a Ladies Detective Agency in Botswana run by Mme Precious Ramotswe--individual titles are escaping my pregnant brain right now, but if you searched on Amazon, you'd find him. These are wonderful books.
*I know that I shouldn't put book titles in quotes, but I have no idea how to underline in this format.