You can have your own customized URL for your facebook profile like facebook.com/username. It will make your profile more attractive and you can easily refer someone to your profile by giving this easy to remember facebook URL.
The another benefit of making customized URL is that you will automatically get username@facebook.com email address.You can use this new email address (username@facebook.com) to login into your facebook account

Trick to Create a Facebook Username :-

• Login in to your Facebook Account.

• Click on Account >>> Account Settings.

•   Look for the Username field and click on the Edit button.

•   In the text box type your username that you want to set. Facebook server will check for the username in its database whether it is available or not.

•  After giving your username click on Save Changes button and go to your Profile. 
•  You will see your profile link as www.facebook.com/username.

 NOTE: While setting up your username be careful because you can create this username only once.


Trick to Get @facebook.com Email Address:

To set up a  @facebook.com address, go to your Messages view and click the Claim your Facebook email link.
Now, you will also be able to login into your Facebook Account with @facebook.com rather than any other Email Address. At the Facebook login Page enter your facebook username along with @facebook.com, example: username@facebook.com and enter your password.
Your Facebook homepage will be open.