Alex,
How long was this book? How techincal was it? I don't read anything but technical books. I eventually started to treat each chapter of the book as a separate book. I also super read and dipped / skittered. I really find unless I have a specific (very specific) purpose, skittering helps me to quickly absorb everything that pertains to what I want to learn. More often than not I don't make multiple passes through the book. I started photoreading in hopes of reading more material in less time.