You do not "get" a callback URL. The callback URL refers to the location of the server that is hosting your application. For instance, MyFBGame might be hosted at www.myfbgame.com. Some basic details can be found at http://developers.facebook.com/get_started.php.
A "callback URL" is the web address an API needs to send information for use in a different web site.For example, a web developer is building a web application for use in conjunction with another web service's API (such as Facebook or Last.fm). The application is hosted on the web developer's server, and the other web service stores the callback URL so that it knows where to send information when it is requested by the developer's application.http://www.encomsolution.com
A "callback URL" is the web address an API needs to send information for use in a different web site. For example, a web developer is building a web application for use in conjunction with another web service's API (such as Facebook or Last.fm). The application is hosted on the web developer's server, and the other web service stores the callback URL so that it knows where to send information when it is requested by the developer's application. See Also: http://en.wikipedia.org/wiki/Callback_(computer_science)
facebook.com
Open Google and type Facebook you will get many result the very 1st option is long in to facebook click. doing so you can find facebook URL
To get on Facebook, simply type www.facebook.com on your URL bar.
Open Google and type Facebook you will get many result the very 1st option is long in to facebook click. doing so you can find facebook URL
SHAZAR
Yes you can. the URL for mobile is m.facebook.com
A Facebook Username is for your "special" page URL. Say if you used "Waffles" as your username (if it was available) your Facebook URL would be "www.facebook.com/Waffles", also, you can use your username in place of your email when you sign in.
a callback is when you call someone back !!!
http://thefacebook.com/
Use your phone