Peek-o-Matic for Admins

Peek-O-Matic is a free AppleScript which allows you to run an application as another user.
You bind an app permanently to the script by drag-and-drop and then it asks for a user name and remembers that, too.

Henceforth, launching Peek-O-Matic launches above app as above user. Re-configure it by dropping a different app.