Our office (engineering education grad students) currently looks like this. It's usually full of empty desks because people don't work here because... seriously, why would they?
There's been a "what can we do about this?" call recently, so I thought I'd pitch in my idea. Sofas in the back, moveable tables and chairs in the front, whiteboards on the wall, a communal bookshelf, a projector so we have a place to practice presentations. For keeping individual things, we'd have a bank of lockers or drawers or shelves or something of the sort in one of the smaller offices off to the side.
Effectively, I'm suggesting we make the office into a lounge where folks can work. (Not pictured: power strips, everywhere. Also on exhibition: the fact that I didn't realize I should scroll to the left and keep on drawing. Whoops. Oh well.)
For those who want to do their own sketching, here's a blank version of the office. Have fun!