[ubuntu] How to add a user to a group (GUI)

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http://ubuntuforums.org – Title says it all; OS is standard Ubuntu 12.04LTS. I had a close call today where I removed all groups from my administrative user account while using usermod; I managed to revert the changes back but it was close to a disaster. Reason for using usermod was that could not find a way add a user to a group while using system settings -> user accounts. So where is the hidden option in system settings -> user accounts that I'm looking for? Or is there a decent GUI utility for user management? PS I'm convinced that older versions (10.04, 8.04 and 6.06) had the option easily accessible in th (Hardware)