Here's how you can create short URLs using Bit.ly services

/* returns the shortened url */ 

function get_bitly_short_url($url,$login,$appkey,$format='txt') 

{ 

    $connectURL = 'http://api.bit.ly/v3/shorten?login='.$login.'&apiKey='.$appkey.'&uri='.urlencode($url).'&format='.$format; 

    return curl_get_result($connectURL); 

}

/* returns a result form url */ 

function curl_get_result($url) 

{ 

    $ch = curl_init(); 

    $timeout = 5; 

    curl_setopt($ch,CURLOPT_URL,$url); 

    curl_setopt($ch,CURLOPT_RETURNTRANSFER,1); 

    curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout); 

    $data = curl_exec($ch); 

    curl_close($ch); 

    return $data; 

} 

/* get the short url */ 

$tweet = get_bitly_short_url('URL','login_id','app_key');


$tweet = urlencode($tweet);