- Pull out the cable / disconnect the Wifi.
- Block certain websites (i.e. facebook) during work hours. If you use Firefox, an addin called "self control" may do the trick.
- Work offline.
- Disable notifications.
- Clear emails only once a day.
- For the time when you need to send an email: create a 'sending mail' link, with a shortcut referring to "mailto:" (the bit inside the quotes). This will open your email sending application without checking for new mail. You can put this shortcut on the desktop, start menu and/or 'quick launch' bar.
- For the time when you need to find an email, use google desktop to index your gmail or outlook emails (I don't usually use the rest of the desktop search functionality, so I just search my gmail; this also works for outlook).
- Avoid difficult, intellectual, or contraversial discussions that use email - at all times, and especially during work hours. There is a role for such discussions - mostly to construct something of value - i.e. they should aim for publication in a peer reviewed journal, newspaper, or website. Face-to-face discussions may also be useful.
- NowDoThis.com is a website that prevents multitasking/distraction by telling you exactly what to do next. It can be integrated into your desktop using the 'active desktop' functionality; or it can be added as a sidebar to your (e.g. firefox) browser.