This is one of his books where the funny parts are mostly subtle, but are still good. One of our members classified it as a beach read.
There are so many references to other stories and movies that it's hard to get them all. During the meeting, the guy next to me said something that made me remember "A Boy and His Dog." You see, there's another planet out there where dogs are the dominant intelligent species and their pets are short humans. They're better at math than most of us, so when they hear our music, they think of it as math burning up their brain. They can't do anything else. They sent a bomb to Earth to blow it all up so they won't get the music, but the bomb is gone and nothing happened. They send a second bomb which doesn't blow up either. They also send spies in a warship who can't find the bombs. An American gets pulled into all the conflict at the right time.
You need to read the end, and you'll need to read it a few times to get all the subtle things.
I really liked this.