I just found out about this book. It came out back in 1999, so things have only gotten worse since then, but it still might be worth the .33 cents you can pick it up for used on Amazon. One reviewer wrote,
"An exhaustively researched and wittily written expose of the American fundamentalism and televangelism. Diamond exposes the crimes and follies of almost every major "Christian" leader, from Pat Robertson to Oral Roberts. Incredible journalism, and a shockingly entertaining read to boot."
I've added it to the Snake Oil Amazon store.