Sometimes you might want to provide local admin permissions to an Active Directory user.

This can be archived by different solutions:

Automatically obtain the settings from the AD using the Directory Utility

Add an AD group to the local admin group (as described here)

sudo dseditgroup -o edit -a "DOMAIN\group name" -t group admin

Add the domain user to the local admin group

sudo dseditgroup -o edit -a usernametoadd -t user admin

More information can be found at the “Managing OS X Blog”

PS: Maybe you are also interested in how the change the ID of a user the right way.