Gravatar (an abbreviation for globally recognized avatar) is a service for providing globally unique avatars which was created by Tom Preston-Werner. On Gravatar, users can register an account based on their email address, and upload an avatar to be associated with the account. Gravatar plugins are available for popular blogging software; when the user posts a comment on such a blog that requires an e-mail address, the blogging software checks whether that e-mail address has an associated avatar at Gravatar.
PHP:
function GetAvatar($email)
{
$emailMD5 = md5($email);
$gravatarURL = "http://www.gravatar.com/avatar/" . $emailMD5 . ".jpg";
$html="<img src='$gravatarURL' />"; return $html;
}
C#:
public string GetAvatar(string Email)
{
string emailMd5 = Utilities.Encryption.MD5.ComputeHash(Email.Trim().ToLower()).ToLower();
string gravatarURL = "http://www.gravatar.com/avatar/" + emailMD5 + ".jpg";
string html = "<img src='" + $gravatarURL + "' />"; return html;
}