Profile Changes Notifier
This plugin for Joomla 2.5 checks the changes in the User Profile and notifies an admin.
Every time a user edits his/her profile, it checks the name, username and e-mail. If any of this information differ, it sends an e-mail to all administrators with system notifications switched on.
The notification contains the changes and the previous state.
It is a great tool for admins that want to have up-to-date information about their users.