I can vouch for the convenience of BART. They put in an extension directly to SFO (in fact, to the international terminal). On my recent flight out of SFO, I took a casual carpool a block from my apartment in Oakland, got dropped off at the Embarcadero, hopped on BART, and I was at SFO before I could finish reading the front section of the Chronicle. Talk about awesome.

BART does have a slight hitch. The ticket price to SFO is $4.95 from the SF financial district. Everywhere else in the area of SFO (even stations farther away) are under $4.00. But they grab you by your danglies and squeeze, because it's still considerably cheaper than driving there and paying for parking, catching a cab, or heaven forbid, get off BART at the Millbrae station and transfer to a city bus like I did once many moons ago.

For info on BART, just go to http://www.bart.gov . Very convenient, and no problem with your rolling up rights, assuming the escalators are all functioning.

Beware the Cheesecake Factory on the top of Macy's in Union Square, though! We have NEVER been there (weekday or weekend) when the queue wasn't a bear. On weekends it's even worse; we've been told flat out that waits could be two hours+.

The food is great, though, as is the cheesecake. If you're hankering for a Cheesecake Factory cheesecake, take the elevator up to CF in Macy's, and turn right when you exit the elevator... go straight to the cheesecake counter, and order one to go. They will pack and bag it and give you napkins and forks, so you can even take it with you back to SFO if you wanted.

Do visit Union Square if you can. All the holiday decorations are up now (they were finishing up the Christmas tree lights a week ago). It looks very nice.