Listen to music. Get the headphones that encompass your entire ear so you don't hear other people talk. I've done this for 10 years now. Also possibly get people to write you emails instead of dropping by the office even if you're 5 feet away. Work from home or from somewhere else occasionally, and work hours when other people aren't there.
I've started working from one day a week and have found I can get significantly more done away from the office. Maybe going into work a couple hours before others would help too...
