The charming Bahamas tourism campaign seems to be running a new ad campaign in the subways. One poster we saw has suggestions for "Subway snorkeling":
How to Subway Snorkel:
(1) Crowded subway
1. Enter a crowded subway station (for prime viewing, choose the L, the A, or the 4 at rush hour)
2. Float from car to car experiencing all the beauty and diversity of New York's underground animals, from Wall Street sharks to Brooklyn urchins
3. Be respectful of their habitat
But floating from car to car is totally illegal now! Unless you're doing the "rush from train car to train platform to new train car" thing which is a pain. But there is a good idea buried in this - oxygen tanks for your subway journeys. No more smells, though Vicks VapoRub under the nose is less bulky.