I am not sure if anyone else has done it before, but I wrote a php library to bitly api. Bitly Api Php github repo is the place where you can get it.
require("bitly_api.php"); $bitly = new Bitly(array("login" => "yourlogin", "api_key" => "yourapikey")); # or to use oauth2 endpoints $bitly = new Bitly(array("access_token" => "youraccesstoken"); $data = $bitly->shorten('http://www.google.com/');
Currently, it only supports curl to make http queries. I might add php http later on.
Please try, test, comment & contribute.