Good question, and good answer!!! I still get all weepy when I recall the streetcars!! Especially the L Taraval - as a little kid it was my "spaceship" from the Parkside to other parts of The City. (The M car runs a close second...)
When I visited SF in 2010, a dear friend gave me an L Taraval cap as a souvenir. I was thrilled, and it is one of my most treasured possessions. I'm toying with the idea of being cremated with it!! Hahahah. (I think he got it at the Muni Museum gift shop.)
During that visit, I also saw a few "vintage" lines running near the Ferry Building. So clever and retrospective-ish.
I think the only thing that freaked me out was that some cars which now get from West Portal to Downtown go underground these days. I'm a wee bit claustrophobic, and kept praying we would not experience the next "Big One" while traveling thusly.... And, of course, I also missed enjoying the views while passing neighborhoods and businesses on the outskirts of Downtown.
It certainly gave me a new appreciation of New Yorkers who take the subways regularly!!! Brave people!!!