Taxi or Uber in San Francisco

Since May I've had jury duty every Thursday (except for that four-week period where we didn't have to go in, after being told that having a day off was so extremely rare as to be practically unheard-of), which means that I hop on Caltrain to the city (San Francisco, in this case). The Caltrain station in San Francisco is on 4th and King streets, which is a couple of (long San Francisco) blocks from the ball park but is not close to anything else. There are very nice express buses to the Financial Area and to the Twitter headquarters, and buses to other places. There is even a Muni trolley that takes you to the BART stations. However, none of those bus, Muni, or BART lines take me close enough to the federal building for me to want to use them. (Oh, I miss the days when I could walk long distances.)

( Which leaves me with a dilemma... )