A smart reminder from Jakob Nielsen in his most recent Alertbox:

“…the best way to boost your productivity is to switch off IM, Twitter and the like and refrain from checking your email more than once per hour. Even the shortest interruption costs you several minutes of productivity as you switch your brain back into gear for your main task, particularly if you have a knowledge-intensive job.”

(Of course, I share that as a good idea, knowing full well that I’ll continue to keep my e-mail program open and check it more often. I do, however, keep the sound off.)

Nielsen’s 10 steps for cleaning up what he calls “information pollution” include writing informative subject lines and avoiding “reply to all.” He reminds us that “Better prioritization, fewer interruptions and concentrated information that’s easy to find and manage helps people become more productive and stop wasting their colleagues’ time.”

I also encourage people to update the subject line when you have a long string of e-mails that go back and forth, morphing into a discussion about something completely different from the original note. And please, when those back-and-forths start growing in length, cut off some of the unnecessary earlier comments, keeping only the most recent ones needed to make sense of your reply. A telephone call might also save time!