One of my worst nightmares is being stuck on a plane without a good book to read. Happily, after much trial and error — and packing far too many books — I've finally realized what makes a perfect carry-on book:
You want a book — either fiction or nonfiction — that's complex enough to smother your annoyance when the guy in the row ahead reclines his seat into your lap, but not so intellectually challenging that it demands a dictionary. No plotless wonders with paragraph-length sentences; you need to be able to put the book down when the person sitting by the window needs to step over you to get to the bathroom.
Mostly you want something that's intriguing enough to make you forget that you're 34,000 feet in the air and, in your heart of hearts, you don't really understand how the plane stays up.
The books I've chosen meet these criteria beautifully, and, as such, they've all been awarded the Nancy Pearl Wanderlust Award for Great Airplane Reading.