I hear good things about Sam Schlorff's recent work entitled Missiological Models in Ministry to Muslims. I plan to obtain a copy for review and for my own edification. I also recommend the book to my readership.
It isn't exactly on Amazon, but you can find ordering information here. A review of the book in the January 2008 volume of the journal Missiology will probably pique your interest, if you have a copy handy to you. The book itself is under $20 plus S&H. I'll host a conversation after I've read it, so if you read it too, we'll all have an informed dialogue.