I am now reading Adrian Hastings' excellent one-volume history of Christianity, entitled A World History of Christianity. One of the best things about this book is that it gives a truly global history (whereas a lot of church history books only focus on Europe and America). Hastings' text has chapters on Christianity in India, the African continent, Asia, South America, and even Australia (and of course Europe and America).
I'll be teaching a 6-7 week course at our church this summer using Hastings' text. Any interested persons can contact our church office (734-242-5277).