At first I was surprised at the amount of speed and opiates consumed around the Bay Area. Weed and psychedelics seem reasonable given the population, but the more I think about it, the more it makes sense: impressionable kids straight out of college are thrust into extremely fast-paced work lives with too little wisdom and too much cash, so it seems like a natural continuation of the college mindset, i.e., cramming with addy and winding down with weed, by keeping up with coke and numbing down with Vicodin or heroin. The concept of work-life balance approaches insanity in the valley. I'm glad that I left, and I haven't looked back.
I think Silicon Valley is more like Wall Street than they realize. It seems more and more like a playground for the rich where you tough it out for a few years before your resume will let you work wherever you'd like, because unless you're loaded, I can't imagine how anyone would raise children there. Can't be too good for long-term employee loyalty...
San Francisco is the only place I've ever seen custom glass funnels for sale at headshops.
SF is also the only place I've ever seen flyers advertising a Whipit delivery service (nitrous oxide).
Generally speaking SF seems to be much more loose with drug use than other cities in CA - although I will say, from what I've seen, the use of pharmaceuticals like benzos and adderal seem to be treated as lightly as alcohol these days.