Not a book, however..
http://www.musictheory.net/
Click on the tab labeled 'trainers' and it will pop up a handful(chord/interval/scale/note, ect ect) interactive training devices to practice your ear training with. I have a hard time sticking with it, but it would be hard to ask for anything more.
*now if there was an application like this for some kind of mobile device, i'd be all over it like Oprah on a buttered croissantwich.