(America class-less? Hardly.)
Choosing just the right detail or set dressing to illustrate the character's situation and aspirations is fun.
So today's little internet gem (thanks BoingBoing) is a 1949 chart from Life magazine that spreadsheets and illustrates the differences in taste between High-Brow, Upper and Lower Middle-brow, and Low-Brow. See it big n' beautiful HERE.
1942 Life magazine chart of The Good Life, by social/intellectual status level
Hilarious. And, as far as I can judge, pretty darn accurate. I know that in the 1920s the U.S. Census Bureau had a similar sort of checklist that helped workers peg families into their status-holes - so many points for books in the parlor, more points for a piano, a rug, etc. My favorite book to discuss these matters - from the 1980s - is Home Psych, by Joan Kron. (Read an excerpt, "The Semiotics of Home Decor" HERE.)
So what would today's status/class markers be?
Things - objects - are easier come by nowadays than in the past, but I'm pretty sure owning "real" art would still be one marker of high-brow-ness... So would be reading high-toned literature. What else?