This code should get you the user's full name.
With a little tinkering I bet you can also get the email address.
(also set <identity impersonate="true"/> in your web.config)
string Domain_Slash_User = Context.User.Identity.Name;
Domain_Slash_Machine = Domain_Slash_Machine.Replace(@"\", @"/");string
queryString = @"WinNT://" + Domain_Slash_Machine;DirectoryEntry obDirEntry =
new DirectoryEntry(queryString);
System.DirectoryServices.PropertyCollection coll = obDirEntry.Properties;
object obVal = coll["FullName"].Value;_User = obVal.ToString();
Session.Add("UserFullName", _User);