[maaaats]

I agree, team rooms is a suitable middle ground. You get the info and time-saving disrupting between members of the team, and get to ignore stuff from outside the team. If there's people running between all the rooms, a designated "contact person of the day" for each team is a good idea.

[gtirloni]

I think team rooms are a problem if, and only if, they are permanent. I've worked in cubicles, open floors and permanent team rooms and in the later all people did was to use the privacy to surf the web, talk about stupid stuff they would not dare to mention in a open floor. It made it very tricky to concentrate, but at least the problem was concentrate and a talk with the team leader / manager would usually quiet thing down for a while.

Ad-hoc team rooms sound like a very good idea though.