It's not cheating at all, and it's definatly not FAKE. The term comes from "faking" an arrangement to a song using the chort chart to determine the backgrounds. A "Fakebook" still requires a working knowledge of chord structures and theory to be effective,but it can be a lifesaver to a working musician who needs to take requests in a wide area of music styles.
Personally - the best thing you can do as a working player is to get familiar with all the chords. That way you can "fill in" behind a melody or singer without having a sheet of music slowing down your creative juices. You never really "own" the music till you have the notes in your head. Then you can add the expression and individual touches to it.
WE all have to "fake it" sometimes. It's not a bad thing - as long as the client is happy.
Better to take the request and play a skeleton arrangement, then to turn down the chance to please. This is the "business" part of show biz. The "art" part comes in tiny pieces! (Be grateful when it does)

[This message has been edited by Uncle Dave (edited 12-10-2001).]