Originally Posted by
BuildingMyBento
Will check this out, too!
Take a look at Uber Pool, but it would be hard to beat
TWA884's bus suggestion if you're going for the cheapest approach.
ETA: For fun, I just plugged in my home in Berkeley to the Monterey Bay Aquarium. No Pool option; regular Uber for $134. I'm guessing that the Pool concept doesn't work for such long trips between metro areas, with sparsely populated areas in between.