you have a good subject, and a good start. what would really make this photo great would be better lighting. if you waited till the sun was low in the sky, it would cast a nice long shadow which would make the image a little more dramatic. also, try not to place the center of the cross in the center of the picture. black and white might also be nice.
I definitely believe this photo would have more impact if shot from a lower angle... this reminds me of some shots of children I see regularly where the adult is standing above the child pointing the camera in a downward angle... In a situation like this one, it could be better to get down on the level of your subject and shoot at a relatively parallel angle to the ground :) - jmsetzler