A Safari extension to help reduce the amount of time spent on Facebook.
When the extension is installed, facebook.com remains open for a default of only 30 seconds. The user can gain extra time by clicking a countdown box (which [currently] replaces the mostly useless "Find Friends" button in the upper-right corner). This can gain the user up to 55 seconds of extra time (each click adds a number of seconds, starting at 10 but decreasing by 1). When zero is reached, the page's location is changed to another site (by default, the Wall Street Journal).
Obviously, this can easily be bypassed by reopening Facebook. However, most of the time, I waste time on Facebook because I never take the initiative to leave. The extension makes it easier to leave than to stay, which most of the time is all I need.
Planned future updates include pausing the countdown while chats are opened (currently, Safari will prevent the page from leaving while text is entered, but not while chats are being viewed), and giving the user the ability to choose original time remaining and the limit of additional time.