Using ADUC, it can be quite a hassle to find and/or unlock AD accounts. Powershell solves this by providing some neat commands for a system administrator to use.
To list all locked out AD accounts:
Search-ADAccount -LockedOut
To get more info about these accounts, you can do a Full-List:
Search-ADAccount -LockedOut | FL
Furthermore, you can pipe the output to quickly unlock some/all AD accounts:
Search-ADAccount -LockedOut | Unlock-ADAccount