Emad Ibrahim

public static class BitlyApi
{
    private const string apiKey = "[add api key here]";
    private const string login = "[add login name here]";

    public static BitlyResults ShortenUrl(string longUrl)
    {
        var url =
            string.Format("http://api.bit.ly/shorten?format=xml&version=2.0.1&longUrl={0}&login={1}&apiKey={2}",
                          HttpUtility.UrlEncode(longUrl), login, apiKey);
        var resultXml = XDocument.Load(url);
        var x = (from result in resultXml.Descendants("nodeKeyVal")
                 select new BitlyResults
                            {
                                UserHash = result.Element("userHash").Value,
                                ShortUrl = result.Element("shortUrl").Value
                            }
                );
        return x.Single();
    }
}

public class BitlyResults
{
    public string UserHash { get; set; }

    public string ShortUrl { get; set; }
}

var shortUrl = BitlyApi.ShortenUrl("http://www.verylongUrl.com").ShortUrl;