I remember weddings where each table had a cheap disposable camera and guests were encouraged to take snapshots of each other. A good idea, except the quality of the photos was often poor and only the wedding couple were likely to see them.
Today guests don't need need throw-away cameras, they all have cameras built into their mobile phones. And photo-sharing apps like CapsuleCam and Eversnap let them immediately join in the fun.
Social media platforms like Facebook and Picasa offer photo-sharing services, but Capsule is a more private option where access to the images is restricted to a selected audience. Guests can download the free CapsuleCam app for Apple or Android phones, then enter a code to for access to an album created just for the event. The album is online for everyone to see and can be shared live at the event.