You can stop computer-based slacking — like the compulsive reloading of Digg or Reddit at the expense of productivity — with a few changes to your computer’s DNS profile, and enforce the changes using Lockout, a tool designed to enforce discipline and increase productivity.
Lockout’s methods are simple: after configuring your system to prevent slacking, Lockout prevents you from becoming the administrative superuser, root, for a set amount of time. There are only two ways to get root access back: wait until the set amount of time passes and Lockout returns control to you, or reboot the computer. Lockout assumes GNU/Linux users, not accustomed to rebooting, will do something productive while waiting for their systems to unlock.