Try at places you have an "in" at. Places where family works or family friends are managers or places where the boss goes to your church (if you're in to organized religion, I forget)... things like that.
I like to do my own... I'm thinking of a shot of Bill the Butcher from the first scene on the second disk of Gangs of New York, but I'm not set on it. I may go back to my first custom avatar, or make one similar to it.