Of course you bring a book to read at the airport. But did you ever consider reading the airport itself? Christopher Schaberg has made a career of reading the airport and in The Textual Life of Airports, he examines some of the ways airports have been portrayed in literature and film, and considers what the airport has to say to us.
By "reading" the airport, Schaberg seems to mean looking at the airport and thinking about it. Normally, that kind of thing strikes me as being an egghead-ish thing to do. But I've spent a lot of time in airports, and I think I get where Schaberg is coming from. The airport is not your destination, you're only there to get from one place to another, even if you've just arrived, you're still on your way to a hotel, a conference center, home. Yet, it's nothing like a train station or a bus station. I certainly wouldn't want to "read" a bus station.
Schaberg looks at the art in the airport, at the carpet, at the landscaping, the architecture, at the security screening. He reads what novelists have written about airports, analyzes how filmmakers have portrayed airports, listens to airport-inspired music. He spends an entire chapter deconstructing three Hardy Boys books that featured airports.
Fittingly, I found The Textual Life of Airports in a London book store (Foyle's) and read the book on the plane (and airport) returning home to Las Vegas. This really would be an excellent book to stock in any airport bookstore.