I stole this idea from Tim Ferris's The 4-Hour Workweek book. He has tested the title for his book this way, and I'm thinking of doing the same for the book of WRITING TIPS you asked me for, compiled from these daily posts (it's coming...it's coming).
The way to do it is simple.
Come up with a few title versions—Tim suggests five—then do the cheapest text-based Google ads. They will rotate automatically. Have them point to a page on your site where it says something like "The book is on back order. Thank you for your patience! Please leave your email so I can contact you when I have the copies handy."
Then measure which variant performs the best, and after you settle on a title, get back in touch with those people via email and offer them the book.
I intend to try it. And I'll report my findings here for you, so you can take away from it and apply it to your own books.