Time Blocked for Chrome
More About Time Blocked
You can with ease dictate the time you want to be blocked from a website, and even allow yourself in only on weekends so you don't unblock yourself, and "forget" to block yourself again!
Feature suggestions are encouraged, but I will only implement features which makes this plugin simpler to use.
This plugin was made on a request: http://www.reddit.com/r/SomebodyMakeThis/comments/1igrkt/a_chrome_extension_that_prevents_me_from_visiting/