Private Function ObtenerMD5(ByVal email As String) As String
‘Source: http://hanzcocchi.net/implementar-gravatar-en-asp-net/ in C#
Dim md5 As MD5 = MD5CryptoServiceProvider.Create()
Dim encoding As ASCIIEncoding = New ASCIIEncoding
Dim stream As Byte() = md5.ComputeHash(encoding.GetBytes(email))
Dim sb As StringBuilder = New StringBuilder
Dim i As Int16
For i = 0 To stream.Length – 1
sb.AppendFormat(“{0:x2}”, stream(i))
Next
Return sb.ToString()
End Function

Saludos,