Although RUSA does not yet recognize a photo control, I would like to see it added to the permanent rules. However, instead of simply asking for a photo of some landmark, I would require a simple composition. For example, riders would need to take a photo of their bicycles facing left in front of the Anytown city limit sign.
The downside of a photo control is that riders would need to carry a camera. But just about everyone has a camera (it's hard to find a cell phone without one), so it would not be an onerous requirement.