One person I really wanted to find in the 1940 US Census was my great-great-grandfather's brother, Albert Rendle Croad. He lived in Salt Lake City for many years but died in Arizona. I wanted to know which locale he was in at the time of the census. I did a quick search through Salt Lake City directories and found him living at 132 B St., Apt. 1 (which just happens to be a few blocks from the Family History Library).
I was able to find him in ED 30-120, image 22, with his wife and son:
All three had 4th grade educations. Lucy was the land lady of their apartment house; Albert R. was a houseman at either the Whitehouse (1940 city directory) or Reid Hotel (1941 city directory).
Albert was the youngest of fourteen children and the only one in the US still alive in 1940.