Administration of Active Directory does not have to be hard. Too often what should be a simple task is made more difficult than it needs to be.The solution? Hyena from SystemTools Software. With ease-of-use as well as powerful importing and bulk updating capabilities.
http://www.microsoft.com/technet/scriptcenter/topics/win2003/lastlogon.mspx
Or
Get a simple one in logon script, it will write down the date, time and the login name to a text file in the server. (But make sure you append it, not overwrite the text file)
echo %computername% %username% %date% %time% >> \\servername\log\log.txt