
I've been ~3 times and there's usually some good stuff. The sale is two days long, and i've only ever been one the second, half price day--so there may have been a lot of stuff go out the door that I wasn't even aware off. Not so good on bikes, or camping supplies, but definately kitchen stuff, a lot of clothes--by the time I'm done with other stuff I'm too tired to go through them, but there's probably something good there costume wise, some furniture, odd bits and pieces, toys (yes, Dr. Pyro, I'll do a Barbiescout), jewelry, bedding (got a great quilt for $3 one year) and all sorts of stuff to warm the heart of a scrounge.
Proceeds benefit the Oakland Museum--a fine institution with which I have no connections. A former art teacher of mine is part of the volenteer corp who puts in on. It's in the warehouse district of Oakland, off 880/the former 17/the Nimitz.
There is also a preview sale with paid admission.
http://www.museumca.org/events/elephant.html