Anyone play that old sim game on PC Bridge Builder? it was 2Dish and you had to build a bridge strong enough for a train to cross. The catch was you only had a limited amount of money for the project, and if you didn't build it well enough, it'd collapse. Super fun, made you feel like an architect. I loved it! It would make a fantastic iPhone game, the closest thing i've seen is tiki towers, but i dont want to have to baby sit monkeys...i just wanna build stuff.