I haven’t read the book, but I’ve download chapter 7 and I think it’s an awesome book. A recommendation for everybody who’s building Google Maps Mashups with Rails.

You can even get it for free. There’s a contest where you can win a copy of the book, they are giving away 3 free copies. They call it a ‘contest’, but all you have to do is leave your name and email address. You have to hurry, because they’ll randomly draw three entries on March 15th, 2007 (deadline is midnight March 14th EDT).

If you haven’t won a copy on the 15th, you could always order a hard-copy (also available as an ebook)

All the examples of the book can be viewed online and the sourcecode can be downloaded.