Hide urself in facebook

Its very simple to be invisible on facebook.

Process:-
1) On the top-right side, go to the tab named Account >> Edit friends.
2) Click on Create list.
3) Name the list. Eg. College friends, Dance crew, etc. and add some 10-15 friends in each.
4) Now, click on home and see the chat list, you could see the chat list being divided into groups you had created.
5) Simply, turn off the green light besides a group to disable urself from being visible to them.

Note:-
The most important thing is if you are invisible to others, then even you can't see others.