Both cities on the water, great seafood cuisine, funky, artsy scene...lots of homeless people, very liberal, lots of taxes, etc.
Just a feeling I got.
There were lots of similarities between SF and Lisbon, Portugal too.
Haven't been to Lisbon so I can't compare. I was just in the Bay Area last month for my cousins's wedding. Spent Thur/Fri/Sat AM in SF, the wedding itself was in Palo Alto. His now-wife wanted an outdoor wedding and it apparently never rains in Palo Alto(it was the afternoon of the wedding however). Lots of fun.