I've been talking about some agile techniques with one of my co-workers, and one of his concerns about pair programming or not being in separate offices is that he won't be able to get into a state of flow in that kind of environment.

My limited experience with working on projects in group settings leads me to believe that the benefit you get from informal collaboration is far more important, but I'd like some more data.

What do you think? Is the lack of time for flow a real issue, and if it is, how do you deal with it? Or do you find that the collaboration is more important.