Expanded Universe is a collection of various short works of Robert A. Heinlein; several short stories, but more interestingly, a lot of non-fiction. Articles on his 1960 trip to the Soviet Union (with his Russian-speaking wife Ginny), his opinion of U.S. education, stuff about antimatter, and predictions for the future originally made in 1950 and updated in 1965 and 1979 when the book was published. Even if you don't agree with his views, it's a very interesting read, and useful in getting a feel for the mood of the U.S. during the mid-20th century.