If a shortened URL begins with http://, don't include it in the shortened url. Saves 7 characters, which is pretty awesome for 140 character max length notices.

lib/util.php

@@ -1414,6 +1414,9 @@ function common_shorten_url($long_url)
 
     curl_close($curlh);
 
+    if(substr($short_url,0,7)=='http://'){
+        $short_url = substr($short_url,7);
+    }
     return $short_url;
 }