Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Both a reference and a geeky browser

As you'd expect from the New York Times, this book has excellent illustrations and clear, concise explanations of how a long list of electronic machines work. I took it out of the library initially but ended up buying a copy to use as a handy reference. I've also browsed through it in a geeky sort of way. My only beef: No index!