I spent the summer of 2004 working with In Ticketing to build their box office will-call interface. I developed a streamlined workflow that used a barcode scanner, magstripe reader, and electronic signature pad to quickly facilitate ticket pick-up for events with 50,000+ attendees. In addition to quality code, this required a high-availability on-site server, and bidirectional mysql database replication across unreliable, 10+ mile wireless network links.
Implemented in PHP/MySQL atop In Ticketing's existing codebase. Bidirectional database sync was accomplished at the application layer, since MySQL didn't have a facility for that in 2004.