Sometimes we need to get something done without the distraction of facebook, twitter or for that matter, linkedin (or some other sites you want to stay away). Here is a tip for how to do it on Mac.
sudo vi /etc/hosts
(note you don’t have to use vi, feel free to use nano or other editor of your choice)
referene entries below
====
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
127.0.0.1 facebook.com
127.0.0.1 www.facebook.com
#127.0.0.1 linkedin.com
#127.0.0.1 www.linkedin.com
127.0.0.1 twitter.com
127.0.0.1 www.twitter.com
====
Then do this in command line.
sudo dscacheutil -flushcache
Reference articles: