gravatar.cs

using (var md5 = System.Security.Cryptography.MD5.Create())
{
    var hash = md5.ComputeHash(Encoding.ASCII.GetBytes("dlidstrom@gmail.com"));
    var sb = new StringBuilder();

    for (int i = 0; i < hash.Length; i++)
    {
        sb.Append(hash[i].ToString("x2"));
    }

    sb.ToString().Dump();
}