Heading over to have a drink with an old friend that is running to Cali, and I wanted to map the bar and the nearest subway. My first question is why Google does not include this as an option.
But at least others have mashed the two, which is handy. The best looking is onNYTurf.
Another great site is HopStop which will tell you which streets to walk down, transfers, stations you will pass… the works. Very easy to use and great for finding your way across the city.