WordPress MU

Is it possible to grant site admin privileges to users other than "Admin"?

yes. there's a box in the backend to add other usernames.

found it! thanks!

Where's this box at. I've added two other users in the backend but they can't see the Site Admin tab.

/wp-admin/wpmu-options.php

Scroll down under the "Administration Settings" heading and there's the box.

Thanks! Found it!