[kmiyer]

Deciding whether it's a good idea to visit depends heavily on your financial / visa situation. If it's feasible, then it's a great idea! I came to Berkeley as an international student without having the opportunity to visit and things turned out just fine, but in retrospect I'd have loved the opportunity to get to know the area beforehand.

As others have said, most students at either Berkeley or Stanford don't live in SF. Staying there makes sense as a tourist though, both are easily accessible through day trips and you get to enjoy SF.

If you do visit Berkeley, a great way to get a feel for it is to sit in on classes. You can see this semester's CS classes here http://www.eecs.berkeley.edu/Scheduling/CS/schedule.html. If you talk to the EECS department before hand they'll be glad to organize a mini-tour for you where can chat with a current student. If that doesn't work out, there are enough Cal students (like myself) frequenting Hacker News who'll be glad to show you around.

Edited to add: http://www.quora.com/Which-place-should-avid-technophile-per... would probably be of interest to you.