Of course I am not sure how you check email, twitter, etc. but you may consider some of these things.
Less motivate and more about lessening the noise...
. If email is making its way to your smartphone and/or email client and grabbing your attention, filter it to folders, don't allow it to reach your Inbox except for the most critical. Depending on your phone (if any) and your mail provider, filtering it to a folder other than Inbox will keep it from alerting your, capturing your attention.
. Do away with links/bookmarks to twitter and other websites. Type urls in the web browser address box manually. This isn't going to stop you from typing twitter.com but it does help me think just a bit about where I am spending my time.
. Do away with "start pages" in your web browser. Have it start on a blank page.
. Sleep/shutdown your computer regularly. If "important things" don't involve the computer then you may be less likely to go twittering if all it takes is a shake of the mouse to wake the screen.