I read this a while ago (and a couple of times since...) because I'm reading another one of Heinlein's books right now and thought of it. Robert Heinlein is good author (The Moon is a Harsh Mistress, Stranger in a Strange Land) who has written some thoroughly silly books, like this one. Look at that cover! Two naked ladies flanking a guy in a robe in front of a giant computer bank. It gets even better when you find out upon reading that he is like 3000 years old and they are female clones of him. Oh, and he eventually gets it on with them. They have to talk him into it.
Nonetheless I really would recommend this book because the author writes quite well and it is enjoyable all the way through, with the possible exceptions of the sections composed of quotations from the main character's memoirs, which are not this text.