This 3 minutes video has one of the best explanations of behavioral psychology behind staying productive and recommends some productivity techniques based on research by Janet Polivy, Kenneth McGraw, John Bargh, Tony Schwartz, etc. You should also check out the companion article The Science of Productivity: A Proven Way to Get More Done (in Less Time)
If you take only one thing away from this video, please take this: overcome the illusion of being more productive surrounded by multitasking. As Nass summarized, it turns out multitaskers are terrible at every aspect of multitasking.
Firoz Ansari 