Wow, your story about the conference room is almost identical to what Joel (Joel on Software) wrote about CEOs who work in open offices "like everyone else".

http://www.joelonsoftware.com/articles/FieldGuidetoDeveloper...

"A fairly common Silicon Valley phenomenon is the CEO who makes a big show of working from a cubicle just like the hoi polloi, although somehow there’s this one conference room that he tends to make his own (“Only when there’s something private to be discussed,” he’ll claim, but half the time when you walk by that conference room there’s your CEO, all by himself, talking on the phone to his golf buddy, with his Cole Haans up on the conference table)."

Thing is, even if a CEO isn't converting a conference room into a private office, even if the CEO is sincerely working in the same office space as everyone else, it still doesn't work. PG wrote about this on a related note in the makers vs managers's schedule. Mild interruptions don't seem like a big deal to managers, and the nature of their jobs means that they'll place constant communication far above quiet, focused, uninterrupted work.