Removing distractions especially at work can boost your productivity, so they say. I gathered some tips from other blogs and added some more to improve your distraction-freeness.
Have a quite workplace. If you must listen to music, many people find it better to listen to instrumental music only (no vocals).
Clear your desk. I'm a minimalist, so I like my desk clean. I think this could also affect my productivity, but I don't really know.
Close all applications and tabs you don't need. I cannot work when I see 30 windows and always have to think where to click. I have an average number of 2 windows in the taskbar and I am a programmer. I find myself periodically killing windows/tabs, when their numbers exceed 5.
Turn off your IM. Or at least turn off the notification of the new messages. Or at least go invisible.
Turn off auto-check on e-mail. You should check for your e-mail once or twice a day. If you have to look on it more, decrease the frequency of auto-checker checks. Auto-checks of e-mail give false sense of urgency.
Filter through your subscriptions. All the kinds. Clean RSS feeds, e-mail subscriptions, etc. If you use Google Reader, it has this nice feature - 'Trends' - which can help you with the cleaning.
Have a zero mailbox. I have it empty for two months now and I still live happily. Move your e-mail from your inbox when you're done with it. Try to read each of your e-mails just once. Take the wanted action (reply, fix something, etc.) and try to immediately decide if you will delete it or archive it.
Clean your computer desktop. There should be no icon, that you don't want to click multiple times per workday. Now I am on seven.