People consistently overestimate their multitasking ability.
There is huge power and efficiency to be gained by batching similar tasks, or "single-tasking" as I like to call it.
Email, social networking, and especially chat programs are notorious for breaking focus and concentration.
I discovered what a difference this makes when I was running my company from New Zealand and all my clients and employees were in North America.
There was a more than a 12-hour time difference, so I was essentially forced to track and batch all my tasks using an early version of PMRobot.
When I got up in the morning, the day had already ended in North America, and I was able to get work done with zero interruptions.
This resulted in a huge productivity boost!
As I'm writing this blog post, I have a number of tabs open for related material, but I've closed Gmail, Twitter, Facebook, and anything that could interrupt my flow.
I do the same thing when I'm programming. Before I open Eclipse to write code, I close everything else that's not related.
What time is it where you are right now? What major goals have you accomplished today? How many interruptions have you had?
Trust me, give single-tasking a try! I guarantee you'll be more productive.