There was a terrific article recently in theWall Street Journal about workplace distractions. It accurately points out that there are a number of factors that lead to being distracted in the workplace. 
Some of there are our of our control, for instance, the density and openness that accommodates the contemporary open office makes it easy — too easy — to interrupt co-workers.
But, it seems, we share some of the blame as well with Facebook, Twitter, emails, and texts demanding our instant attention.
Some solutions are deceptively easy, like using the phone instead of a seemingly endless (and all to often unproductive) chain of emails. Or banning phones and other devices from meetings as demonstrated by Lacy Roberson, a director of learning and organizational development at eBay, who recently instituted a no-device policy during some team meetings, a change that she says has made gatherings more efficient.
If you are in an office with co-workers some amount of spontaneous interaction is inevitable. The key is to manage it.