Fanpictor is a Swiss startup that engages mobile devices in unique concepts at large events.  It ties mobile devices into large light shows and various other forms of fan engagement and analytics.

They apparently use some cool tricks to pull this off:

Fanpictor uses ultra sonic sound waves to deliver data directly to smart phones. Fanpictor leverages existing stadia audio systems and fans’ personal devices to deliver unique, branded experiences. This highly scaleable communications protocol allows teams to engage and communicate with fans without relying on WiFi, bluetooth or cell phone coverage