Just an FYI - if you've got the bar code number you can generate a bar code to get through the gate scanners.  It doesn't help you with the ushers as far as why section you have a ticket for, but it will get you in the door.

Sounds like an easy way to cheat retail stores.  What is the purpose of this technique?  Lost your ticket, but remember the barcode?  I've had the ticket office print me off a new ticket since I'm a STH.