BART in San Francisco (or, how to get to RWA without using a taxi or worrying about catching a shuttle)

I was just chatting with a friend about getting from the SFO airport to the Marriot downtown without being reamed by a taxi fare, and mentioned that I was going to come in on the subway. The Powell Street station is only a block and a half from the hotel, and costs just a little over $5.

And this is an excellent step-by-step guide to using the system from SFO to Powell Street station.

Is anyone else coming in from the airport and using a handy/cheap/easy method of transportation?