We're planning a family vacation to the San Francisco Bay Area & Silicon Valley, and one of the highlights I don't want to miss is the Computer History Museum. However, I didn't find that listed in the free guides we got from our auto club. So:
You should definitively go to the Computer History Museum in Mountain View and especially check out the Stackoverflow plaque in the Computer History Museum Wall.
See also the Meta SO thread about it.
You will definitely want to visit Weird Stuff, which is an enormous warehouse of all kinds of discarded technology located in Sunnyvale. It's a bit out there, but very worth it.
If you're interested in doing any archival research, you might also want to schedule an appointment with Stanford's Silicon Valley Archives.
(Sorry for the late answer)
I've spent about 3 months over the course of a few trips (2 months on my first trip), and I had a list of places I wanted to see. Not all of them are 'attractions' or the usual, but nevertheless something as a geek that's been looking at the things going on in Silicon Valley from a far most of my life I wanted to see:
As I said, not all are 'family attractions' (eg. electronics stores), but things myself and my girlfriend were interested in seeing. I went to the Intel Museum, and although it was somewhat interesting I wouldn't recommend it if you're already going to the CHM, it's tiny and as you can expect, just a timeline of Intel's achievements.
A lot of these are also in The Geek Atlas O'Reilly book, and you might benefit from reading/listening to Microserfs to get a feel for how things were in the early '90s, including the places they went around the area (such as Fry's).
If you love arcade games, you should get a bundle of quarters and go to the Musée Mécanique (Linking to yelp because their official site has auto playing music :S).
I'm surprised noone mentioned the book Geek Silicon Valley
It's been a long while since I read it, and it's 5 years out of date (which is a pretty long time in valley terms), but it has a lot of the sort of thing you're looking for.
I agree with other answers, by the way - the Musee Mecanique, the Computer History Museum, and Weird Stuff are all good choices (I'm not as big a fan of the Tech Museum).
The two I'd mention are the Google Campus, and any of the Fry's outlets (though they're not as unique as they used to be, they do also feature computer history displays, like "First Transistor").
They have a tech museum in San Jose that may be quite savvy, atleast to your tastes.
Of course, you should also visit Palo Alto, not just restricted to Stanford University; it is place known for youthful energy and budding entrepreneurship that is characteristic of the Silicon Valley.
There is the Bay Model Visitor Center. It is a huge warehouse with a model of the bay and all water. Although the model is quite old and inaccurate by today's standards, it shows the efforts required to study the water movements prior to computer simulations.
It is controversial - I liked it, my colleague didn't. Don't expect much interaction there.
http://en.m.wikipedia.org/wiki/U.S._Army_Corps_of_Engineers_Bay_Model
I'd suggest the Lucky Juju Pacific Pinball Museum in Alameda. It's pricey and also loud, so if you plan to spend a few hours there, take earplugs!
If you're carrying a laptop or other Internet-enabled device, you might enjoy spending a few hours in a coworking location or hackerspace.
Get on meetup.com and see what meets your interests and have interesting events going on when you're there. The bay area's really about the amazing collection of people, so meet some!
Silicon Valley Guide has a listing of attractions. The guide is targeted towards tech-enthusiasts visiting Silicon Valley. It has a nice map which gives you a sense for the relative location of the attractions.
