Thank God the Rick Steves books now come in Kindle format. I downloaded the Istanbul and Athens books and could carry them around on my Kindle while we were out walking. Navigationg the maps which have to be zoomed into and scrolled around is not easy, but it beats having to carry books or an iPad.
Great book - gave us several good walking tours and specifically gave us some guidance to see some older parts of the Grand Bazaar so I could see what it originally looked like.