I like Dan Ariely's curiosity, open mind, his data-based approach and his direct style.
The (honest) truth about dishonesty is a fascinating read, challenging our intuitive ideas about who, when and why we all cheat. It is a little bit scarry and sad.
We are pulled between our desire to gain (by cheating) and our image of ourselves as "good" people. The "fudge factor" helps us reconcile them through (obvious) rationalisations.
We cheat for personal gain, but also to help others. Cheating is contagious, through changes in our perceived social norms. There are a few "tricks" to reduce cheating, moral reminders for example. But basically, it's pretty bad.
Understanding what is going on is a first step, but there is no silver bullet...
Good read. On a personal level, but also for managers, teachers and people in other professional settings.