ToTiny

public static class UriMethods
{
    public static Uri ToTiny(this Uri longUri)
    {
        WebRequest request = WebRequest.Create(String.Format
            (
            "http://tinyurl.com/api-create.php?url={0}",
            UrlEncode(longUri.ToString())
            ));
        WebResponse response = request.GetResponse();
        Uri returnUri = null;
        using(System.IO.StreamReader reader = new System.IO.StreamReader(response.GetResponseStream()))
        {
            returnUri = new Uri(reader.ReadToEnd());
        }
        return returnUri;
    }
    #region Reflected from System.Web.HttpUtility
    private static string UrlEncode(string str)
    {
        if (str == null)
        {
            return null;
        }
        return UrlEncode(str, Encoding.UTF8);

    }
    private static string UrlEncode(string str, Encoding e)
    {
        if (str == null)
        {
            return null;
        }
        return Encoding.ASCII.GetString(UrlEncodeToBytes(str, e));
    }
    private static byte[] UrlEncodeToBytes(string str, Encoding e)
    {
        if (str == null)
        {
            return null;
        }
        byte[] bytes = e.GetBytes(str);
        return UrlEncodeBytesToBytesInternal(bytes, 0, bytes.Length, false);
    }
    private static byte[] UrlEncodeBytesToBytesInternal(byte[] bytes, int offset, int count, bool alwaysCreateReturnValue)
    {
        int num = 0;
        int num2 = 0;
        for (int i = 0; i < count; i++)
        {
            char ch = (char)bytes[offset + i];
            if (ch == ' ')
            {
                num++;
            }
            else if (!IsSafe(ch))
            {
                num2++;
            }
        }
        if ((!alwaysCreateReturnValue && (num == 0)) && (num2 == 0))
        {
            return bytes;
        }
        byte[] buffer = new byte[count + (num2 * 2)];
        int num4 = 0;
        for (int j = 0; j < count; j++)
        {
            byte num6 = bytes[offset + j];
            char ch2 = (char)num6;
            if (IsSafe(ch2))
            {
                buffer[num4++] = num6;
            }
            else if (ch2 == ' ')
            {
                buffer[num4++] = 0x2b;
            }
            else
            {
                buffer[num4++] = 0x25;
                buffer[num4++] = (byte)IntToHex((num6 >> 4) & 15);
                buffer[num4++] = (byte)IntToHex(num6 & 15);
            }
        }
        return buffer;
    }
    internal static bool IsSafe(char ch)
    {
        if ((((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z'))) || ((ch >= '0') && (ch <= '9')))
        {
            return true;
        }
        switch (ch)
        {
            case '\'':
            case '(':
            case ')':
            case '*':
            case '-':
            case '.':
            case '_':
            case '!':
                return true;
        }
        return false;
    }
    internal static char IntToHex(int n)
    {
        if (n <= 9)
        {
            return (char)(n + 0x30);
        }
        return (char)((n - 10) + 0x61);
    }
    #endregion
}

Uri longUri = new Uri("http://www.google.com");
Uri shortUri = longUri.ToTiny();