I just posted on another blog about "integrity" and what it means to me personally. Working as a full-time Austin Texas real estate agent and broker/owner for almost eleven years, I have certainly seen my share of agents who lack integrity (and honesty and compassion and knowledge and a host of other desirable characteristics).
To me, integrity means that no matter where you find me (church, home, work, etc.), my actions are consistent. In other words, I don't alter my behavior to suit the group that I am with. Yes, I may have more fun with my friends sometimes, but I wouldn't be embarassed if my wife were there, or the pastor of our church. I realize that this is not an all-encompassing definition, but it helps me to stay a bit more focused and puts things in perspective personally.