OS X productivity application to block access to different websites? I am looking for an OS X application that would block you from accessing certain websites, like social and entertainment one and even hide applications.

The entire purpose is to create a working environment that allows you to focus on your job. 

I have to mention that, the web-browser cannot be banned because it is required to normal use.

Also, the solution I am looking for should provide a way to harden the switching from no-distration mode to unlocked.

This question is about a software solution, so please refrain from recommending books to read regarding productivity.

I realise that using Parental Control and having a managed account would solve some of these but there are some essential problems:


Applications are not hidden, the system just asks for admin password, yuck.
You have to create the list of denied websites yourself, that makes it impossible to manager. Is there a predefined list that we can import?
How to share the documents I'm working on between the two accounts: normal one and restricted one.
I use Antisocial for this:


  Anti-Social is a productivity application for Macs that turns off the social parts of the internet. When Anti-Social is running, you’re locked away from distracting social media sites, including Facebook, Twitter and other sites you specify. With Anti-Social, you’ll be amazed how much you get done when you turn off your friends.


But of course this works only for web sites, not for local applications.