After Richard Dawkins recommended this book in 'THE GOD DELUSION', I immediately sought it out and read it.
It's an enlightening read, not just for (ex-)muslims but anyone who is interested in how this 'great' religion has grown and strongly survived all these years with all its mind-numbingly obvious fallacies.
I found the most interesting topic in the opening chapter which dealt with how and why the West has been soft, sympathetic, blissfully ignorant and politically correct with Islam.
A highly recommended read!
I've attached a 30-page .pdf extract of it discussing the origins of Islam, below.