• choosing a username is optional and will give you a distinct Web address for your profile. It will not change the name that appears on your profile, in search or elsewhere on the site.
It is like an address you are creating.

For eg: If someone asked your id.. you reply with xyz@gmail.com
or @yahoo or @hotmail etc etc

If asked facebook(fb) id??

fb-id looks like

EASY! Just go to the http://www.facebook.com/username/ page and the option will automatically popup! :-)
  • Create your id and give it to your friends as your fb-id.....Bcoz its not easier to find your "name" in the search results among the billion users.. :|