Infinite Sidescroller

What would be the best way in Unity iPhone to create a simple infinitely long level? The game would end when the player is loses.

I've seen functions like Application.LoadLevelAdditiveAsync or Application.LoadLevelAsync. But those are Unity Pro only, and not really for the iPhone. I could also just loop and instantiate prefabs, but how would I prevent the Position values that the player is at from getting maxed out?

You'd have to implement a sort of "treadmill" system, where the player is returned back to the world origin at regular intervals, and the ground, camera, & any other visible gameobjects are also moved at exactly the same moment, by exactly the same distance.

If done right, there should be no visible evidence that the move has taken place, and you can safely continue moving your player in the same direction!