All of our races in OBRA use a finish line camera. I believe it is owned by OBRA and the use is part of the race fee. It usually does a very good job as long as people have thier numbers pinned on correctly.
In one race last year, the camera didn't work properly for the Cat3 sprint finish. The racers all lined up how they thought they finished to get the top 10 (the race was part of a series with points for the top 10). All the racers sorted out the top 10 without a single disagreement - it was really quite surprising.