I picked up a copy of Ian Fleming's Casino Royale and for the last couple of months it's been what I refer to as a knockaround book. It ends up being read when I have a couple of minutes here or there. In the old days I always kept one in the car so when Wife Number One and Only went shopping, I could stay in the parking lot. They also come in handy while waiting in lines for the auto ferry across Puget Sound. The best knockaround books are usually old classics that are thin and portable. I don't much care about the story other than that it is a better time waster than staring out the window.
The first Bond book is interesting in that it is clearly not publishable in today's market. I'm a third of the way through and other than one good bomb going off, nothing much has happened. Bond has eaten several fine meals and met with Mathis and Vesper Lynd and there are some nice descriptions of the casino and a three page treatise on the game of baccarat. If a submission started out like this nowadays it would be bounced by the slush reader before page ten.
You can learn a lot from the classics.