Ask HN: Finding roommates in (south) bay area?

If you're a new-grad moving to the bay area for a new job and shopping for apartments, you most likely (a) don't know many people in the area and (b) want a roommate to lower rent. More so, there are probably hundreds other people in the same exact situation!

So, if you've been such a person (as I am now!), what have you found to be the best way of finding roommates?

Thanks :)