I'd include:
1) Hacker Dojo (conveniently near YC!) -- a slightly-more-corporate hackerspace
2) Computer History Museum
3) Weird Stuff and the other used hardware vendors
4) Drive by the "HP Garage" in Palo Alto
5) Facebook's new offices
6) In-N-Out
7) The Old Pro in Palo Alto
8) Drive by Moffett Field (and go inside if you can; there are events there a couple times per year)