I got this idea from my brother, and I think its awesome. He was using it to design album covers, but it totally works for book titles too.
First trick is to go to to the main page of Wikipedia and click "Random Article" in the top of the left sidebar. Then keep clicking random and see what comes up. Here are 5 title examples I've got from Wikipedia:
-Pas de Deux
-Crow-stepped (from crow-stepped gable)
The other cool trick is to use the random quotes page from QuotationsPage.com. What my brother does is use the last few words of the last quote on the page. Here are some examples:
-Whistle for Him
-A Bushel of Brains
-Devourer of All Things
-Hanged to a Lampost
Just keep refreshing and you get lots of cool things.
One last thing. To expand and further develop your title ideas, check out the 'Last 7 Days' page on Flickr, and then imagine the top right corner photo as your book cover. That way it gives you even more to work with, and helps you get more ideas. For example, lets take the title 'Devourer of All Things'. Pretty interesting title that calls to mind a lot of ideas. But let's put it with the top right corner picture from Flickr, which for me right now, is this:
The picture adds to the already interesting title. This picture gives us a character (nervous looking bride) and a situation (a wedding). So who's the "devourer"? The bride? The groom? A jealous rival?
Just a great way to get ideas flowing, and I thought I'd share. What do you think?