How often are you interrupted during the day? Do you have the new email notifier turned on? How often is that thing going off? How often are you seeing IMs coming in, both personal and professional? Twitter? facebook? Yup, those too are major enemies to productivity.
You may not have it that bad. Your company may lock down some of the social media services which eliminates a lot of the distractions. For many of us out there we are getting bombarded by interruptions. And as a programmer, it is horrible for productivity.
I think Jason Fried from 37Signals has summed it up best in this snippet from his BigThink interview.
So do yourself a favor, turn off your IM, your email etc. Avoid tapping your co-worker on the shoulder when an email will work out just as well. And get back to getting stuff done!