I've only got two more trophies to go and to get them I need to play through the game twice, once on hard mode and once on challenge mode. I want to kill two birds with one stone, though when I start challenge mode then it just drops me right into a medium difficulty play through. You can change the difficulty in the menu, though I read somewhere that you need to have been playing on hard mode from the start. Does anyone know whether changing the difficulty to hard right away will still get me the trophy, or does anyone know how to set up a challenge mode play through in hard mode? 
Cheers, I need to get this game out of the way so that I can continue with Dragon Age.