I had the privilege of working and sleeping in the original Craigslist office/house in San Francisco. It was just another typical, ageing house they had rearranged a little to have a ton of deskspace in the main area. A lot of start ups (including Zappos IIRC) had also been there over the years. They had a mattress in the loft/attic you could crash on if you were up late too.