I wonder how programmers in such environments can get in the "zone" and stay in it for extended periods of time, if they are being "constantly communicated with".
My experience at large tables has been that good coders and PMs will actually IM a developer when they need to ask a question -- I do this all the time even when I'm sitting 2 feet from the guy I need to talk to: "let me know when you have a sec to talk about X", etc.
Again, that's evidence of a team that's generally on-task and communicating well -- a cultural quality that is itself harder to find than not.
It's also a nice courtesy to IM someone before dropping by their desk so they aren't surprised and you can check if it's a bad time.
This will increase your capacity for involved/interesting ideas, make recovering from interruptions faster, and slow you down slightly (but not enough to completely offset the benefits).