Many times while working with twitter or its tweet you want to get the twitter profile of a twitter user. Usually in web you can get this via -

http://twitter.com/username
It loads the timeline of that user with its profile information. But it can not be used in your program because its simply a web page. 
Twitter solves this problem by giving you the XML of a user’s profile information. You just have to modify the above URL like -
 http://twitter.com/users/username

Now, its a simple XML which you can easily read by PHP script. Here is a method that helps you getting the profile information. 
/************************* Twitter Get Profile *********************/
//@ param1 – username 
//return  – An associative array with the profile information.

**********************************************************************


 function profileXML($user)
   {
   $profile=array();
   $xmlDoc = new DOMDocument();
   $xmlDoc->load(“http://twitter.com/users/show.xml?screen_name=”.$user);

   $x = $xmlDoc->documentElement;
   
   foreach ($x->childNodes AS $item)
     {
 if($item->nodeName==”id”)
 $profile[“id”]=$item->nodeValue;
  
 if($item->nodeName==”name”)
 $profile[“name”]=$item->nodeValue;
 
 if($item->nodeName==”screen_name”)
 $profile[“screen_name”]=$item->nodeValue;


 if($item->nodeName==”location”)
 $profile[“location”]=$item->nodeValue;


 if($item->nodeName==”description”)
 $profile[“description”]=$item->nodeValue;


 if($item->nodeName==”profile_image_url”)
 $profile[“profile_image_url”]=$item->nodeValue;
  
 }
return $profile;
}
Now, lets take an example of say barackobama , a well known twitter user. 
Lets find his profile information like -


$userArray=profileXML(“barackobama”);

print_r($userArray);

?>

And , you should also notice that we did not require any registration,twitter API and authentication  for the same.