I bring some absorbing books. What "absorbing" means will vary with the individual, of course. Some things that have tided me personally over recent plane trips are detective/thriller novels by Lionel Davidson, Joe Gores, Robert Parker, Donald Westlake, Peter Lovesy, Jonathan Gash, and Reginald Hill. (I don't mention Hammett or Chandler since I've long ago read all their books about five times, but if you haven't they might be good choices.) Any historical novel by Robert Graves or Mary Renault is good for putting you into that trance, especially if you're going to Greece. I admit with some embarrassment that I took The Da Vinci Code on one flight and it did the job, but I can plead in mitigation that the paperback was on sale in the airport book shop, and since I was about to board a flight for Paris I figured this would be a good time to read it if I ever did.

On a recent trip I took the old historical novel Quo Vadis, which I found much better and more absorbing than I'd expected, though it helps if you're already interested in ancient Rome. It's nice and long. And on plane trips before that I've taken Wilkie Collins' The Moonstone and The Woman in White, both of which I found hefty and entertaining reads.

A lot of these books are available supercheap in paperback in used book stores.