At my old job, there was a lot of unspoken pressure to show up right at 9:00 a.m. Of course, I never really managed to do that consistently, but I tried. Given the 35-40 minute ride on the F train to get there, I would shoot for getting to the subway platform around 8:25 or so. Typically my fellow commuters were dressed up more than I was, and I tended to wear jeans and a non-dressy collared shirt. Maybe one out of every ten people had a Blackberry or iPhone on which they checked their email during the brief above-ground stint at Smith-9th St. When I got to 23rd St, almost the entire train emptied out with me.
At my new job (where I have the exact same commute), I'm expected to show up more like 10:00 a.m. I get to subway platform around 9:15. There are actually about as many people at this time, if not more, but they're mostly dressed down like me. Maybe one in four has a smartphone. Most of them get off further down in Manhattan. Perhaps I am seeing the difference between more traditional office jobs and the “new media” sector.