MemoryStream ms = new MemoryStream();
            pictureBox1.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            byte[] i = ms.ToArray();
            using (var w = new WebClient())
            {
                var values = new NameValueCollection
                {
                    { "key", "433a1bf4743dd8d7845629b95b5ca1b4" },
                    { "image", Convert.ToBase64String(i) }
                };

                byte[] response = w.UploadValues("http://imgur.com/api/upload.xml", values);

                XDocument g = XDocument.Load(new MemoryStream(response));
                string direct_link = "";
                foreach (XElement x in g.Elements())
                {
                    if (direct_link == "")
                    {
                        direct_link=x.Element("original_image").ToString();
                    }
                }
                direct_link = direct_link.Substring(16, direct_link.Length-33);
                MessageBox.Show(direct_link);
            }