Full post here: http://blogs.hbr.org/schwartz/2012/03/the-magic-of-doing-one-thing-a.html
In the past, the focus has always been on doing more at the same time. Multitasking equals increased productivity, right? This article states the opposite, and I agree. I know from personal experience that trying to do 3, 4, 5, or more things at the same results in thrashing that absolutely destroys my productivity. So much time is spent switching between tasks that nothing is ultimately accomplished.
One of the methods that you can use to help keep focused is called The Pomodoro Technique. The idea here is simple: get yourself a 25 minute timer, pick a task, and work on that task uninterrupted for 25 minutes. After each interval, you get a short break to collect yourself and rest, and then you start again. After 4 intervals, take a longer break. Keep a list of your tasks on a blank piece of paper. When interruptions that need your attention occur, add them to your list but do not let them distract you. Getting behind on email? Make it a task! This is a great way to improve your time management. As a bonus, you get a documented log of all that you’ve accomplished in a day!
However you do it, try to focus on a single task at-hand, and I bet your productivity will skyrocket!