I really recommend Stocard (
http://stocardapp.com)
It can make a "ticket" from any barcode, and it becomes launchable from your lock screen (I assume there are iphone/android differences). I added my season ticket holder card to it, and if I ever end up with a different ticket I can just use the camera to scan it in. The ushers like it because it makes the barcode friggin massive and it automatically jacks the brightness on your screen, so it scans every time.
It's been so incredibly nice to not print anything off or worry about leaving something behind.