The Metropolitan Etiquette Authority
Jayshells, you are my favorite person of the week. The artist has created a new "Subway Etiquette" campaign designed to address passengers' most common complaints--about other passengers. Posters will soon be up in trains throughout the city.
Believe it or not, nail clipping (as mentioned above) is a fairly common sight on New York City public transportation. And there's always some dude with a finger up his nose. Come on, people!